Bump version

Add Arch Linux installation instructions

README.md

@@ -48,6 +48,8 @@ Third party libraries and resources:
 * [Mixkit sound](https://mixkit.co/free-sound-effects/notification/) (Mixkit Free License) used as notification sound
 * [Lato Font](https://www.latofonts.com/) (OFL) is used as a font in the Web UI
 * [GoReleaser](https://goreleaser.com/) (MIT) is used to create releases
+* [go-smtp](https://github.com/emersion/go-smtp) (MIT) is used to receive e-mails
+* [stretchr/testify](https://github.com/stretchr/testify) (MIT) is used for unit and integration tests
 * [github.com/mattn/go-sqlite3](https://github.com/mattn/go-sqlite3) (MIT) is used to provide the persistent message cache
 * [Firebase Admin SDK](https://github.com/firebase/firebase-admin-go) (Apache 2.0) is used to send FCM messages
 * [github/gemoji](https://github.com/github/gemoji) (MIT) is used for emoji support (specifically the [emoji.json](https://raw.githubusercontent.com/github/gemoji/master/db/emoji.json) file)

cmd/serve.go

@@ -22,10 +22,13 @@ var flagsServe = []cli.Flag{
 	altsrc.NewDurationFlag(&cli.DurationFlag{Name: "cache-duration", Aliases: []string{"b"}, EnvVars: []string{"NTFY_CACHE_DURATION"}, Value: server.DefaultCacheDuration, Usage: "buffer messages for this time to allow `since` requests"}),
 	altsrc.NewDurationFlag(&cli.DurationFlag{Name: "keepalive-interval", Aliases: []string{"k"}, EnvVars: []string{"NTFY_KEEPALIVE_INTERVAL"}, Value: server.DefaultKeepaliveInterval, Usage: "interval of keepalive messages"}),
 	altsrc.NewDurationFlag(&cli.DurationFlag{Name: "manager-interval", Aliases: []string{"m"}, EnvVars: []string{"NTFY_MANAGER_INTERVAL"}, Value: server.DefaultManagerInterval, Usage: "interval of for message pruning and stats printing"}),
-	altsrc.NewStringFlag(&cli.StringFlag{Name: "smtp-addr", EnvVars: []string{"NTFY_SMTP_ADDR"}, Usage: "SMTP server address (host:port) to allow email sending"}),
-	altsrc.NewStringFlag(&cli.StringFlag{Name: "smtp-user", EnvVars: []string{"NTFY_SMTP_USER"}, Usage: "SMTP user (if e-mail sending is enabled)"}),
-	altsrc.NewStringFlag(&cli.StringFlag{Name: "smtp-pass", EnvVars: []string{"NTFY_SMTP_PASS"}, Usage: "SMTP password (if e-mail sending is enabled)"}),
-	altsrc.NewStringFlag(&cli.StringFlag{Name: "smtp-from", EnvVars: []string{"NTFY_SMTP_FROM"}, Usage: "SMTP sender address (if e-mail sending is enabled)"}),
+	altsrc.NewStringFlag(&cli.StringFlag{Name: "smtp-sender-addr", EnvVars: []string{"NTFY_SMTP_SENDER_ADDR"}, Usage: "SMTP server address (host:port) for outgoing emails"}),
+	altsrc.NewStringFlag(&cli.StringFlag{Name: "smtp-sender-user", EnvVars: []string{"NTFY_SMTP_SENDER_USER"}, Usage: "SMTP user (if e-mail sending is enabled)"}),
+	altsrc.NewStringFlag(&cli.StringFlag{Name: "smtp-sender-pass", EnvVars: []string{"NTFY_SMTP_SENDER_PASS"}, Usage: "SMTP password (if e-mail sending is enabled)"}),
+	altsrc.NewStringFlag(&cli.StringFlag{Name: "smtp-sender-from", EnvVars: []string{"NTFY_SMTP_SENDER_FROM"}, Usage: "SMTP sender address (if e-mail sending is enabled)"}),
+	altsrc.NewStringFlag(&cli.StringFlag{Name: "smtp-server-listen", EnvVars: []string{"NTFY_SMTP_SERVER_LISTEN"}, Usage: "SMTP server address (ip:port) for incoming emails, e.g. :25"}),
+	altsrc.NewStringFlag(&cli.StringFlag{Name: "smtp-server-domain", EnvVars: []string{"NTFY_SMTP_SERVER_DOMAIN"}, Usage: "SMTP domain for incoming e-mail, e.g. ntfy.sh"}),
+	altsrc.NewStringFlag(&cli.StringFlag{Name: "smtp-server-addr-prefix", EnvVars: []string{"NTFY_SMTP_SERVER_ADDR_PREFIX"}, Usage: "SMTP email address prefix for topics to prevent spam (e.g. 'ntfy-')"}),
 	altsrc.NewIntFlag(&cli.IntFlag{Name: "global-topic-limit", Aliases: []string{"T"}, EnvVars: []string{"NTFY_GLOBAL_TOPIC_LIMIT"}, Value: server.DefaultGlobalTopicLimit, Usage: "total number of topics allowed"}),
 	altsrc.NewIntFlag(&cli.IntFlag{Name: "visitor-subscription-limit", EnvVars: []string{"NTFY_VISITOR_SUBSCRIPTION_LIMIT"}, Value: server.DefaultVisitorSubscriptionLimit, Usage: "number of subscriptions per visitor"}),
 	altsrc.NewIntFlag(&cli.IntFlag{Name: "visitor-request-limit-burst", EnvVars: []string{"NTFY_VISITOR_REQUEST_LIMIT_BURST"}, Value: server.DefaultVisitorRequestLimitBurst, Usage: "initial limit of requests per visitor"}),
@@ -68,10 +71,13 @@ func execServe(c *cli.Context) error {
 	cacheDuration := c.Duration("cache-duration")
 	keepaliveInterval := c.Duration("keepalive-interval")
 	managerInterval := c.Duration("manager-interval")
-	smtpAddr := c.String("smtp-addr")
-	smtpUser := c.String("smtp-user")
-	smtpPass := c.String("smtp-pass")
-	smtpFrom := c.String("smtp-from")
+	smtpSenderAddr := c.String("smtp-sender-addr")
+	smtpSenderUser := c.String("smtp-sender-user")
+	smtpSenderPass := c.String("smtp-sender-pass")
+	smtpSenderFrom := c.String("smtp-sender-from")
+	smtpServerListen := c.String("smtp-server-listen")
+	smtpServerDomain := c.String("smtp-server-domain")
+	smtpServerAddrPrefix := c.String("smtp-server-addr-prefix")
 	globalTopicLimit := c.Int("global-topic-limit")
 	visitorSubscriptionLimit := c.Int("visitor-subscription-limit")
 	visitorRequestLimitBurst := c.Int("visitor-request-limit-burst")
@@ -95,8 +101,10 @@ func execServe(c *cli.Context) error {
 		return errors.New("if set, certificate file must exist")
 	} else if listenHTTPS != "" && (keyFile == "" || certFile == "") {
 		return errors.New("if listen-https is set, both key-file and cert-file must be set")
-	} else if smtpAddr != "" && (baseURL == "" || smtpUser == "" || smtpPass == "" || smtpFrom == "") {
-		return errors.New("if smtp-addr is set, base-url, smtp-user, smtp-pass and smtp-from must also be set")
+	} else if smtpSenderAddr != "" && (baseURL == "" || smtpSenderUser == "" || smtpSenderPass == "" || smtpSenderFrom == "") {
+		return errors.New("if smtp-sender-addr is set, base-url, smtp-sender-user, smtp-sender-pass and smtp-sender-from must also be set")
+	} else if smtpServerListen != "" && smtpServerDomain == "" {
+		return errors.New("if smtp-server-listen is set, smtp-server-domain must also be set")
 	}
 
 	// Run server
@@ -111,10 +119,13 @@ func execServe(c *cli.Context) error {
 	conf.CacheDuration = cacheDuration
 	conf.KeepaliveInterval = keepaliveInterval
 	conf.ManagerInterval = managerInterval
-	conf.SMTPAddr = smtpAddr
-	conf.SMTPUser = smtpUser
-	conf.SMTPPass = smtpPass
-	conf.SMTPFrom = smtpFrom
+	conf.SMTPSenderAddr = smtpSenderAddr
+	conf.SMTPSenderUser = smtpSenderUser
+	conf.SMTPSenderPass = smtpSenderPass
+	conf.SMTPSenderFrom = smtpSenderFrom
+	conf.SMTPServerListen = smtpServerListen
+	conf.SMTPServerDomain = smtpServerDomain
+	conf.SMTPServerAddrPrefix = smtpServerAddrPrefix
 	conf.GlobalTopicLimit = globalTopicLimit
 	conf.VisitorSubscriptionLimit = visitorSubscriptionLimit
 	conf.VisitorRequestLimitBurst = visitorRequestLimitBurst

docs/config.md

@@ -36,7 +36,7 @@ Subscribers can retrieve cached messaging using the [`poll=1` parameter](subscri
 [`since=` parameter](subscribe/api.md#fetch-cached-messages).
 
 ## E-mail notifications
-To allow forwarding messages via e-mail, you can configure an SMTP server for outgoing messages. Once configured, 
+To allow forwarding messages via e-mail, you can configure an **SMTP server for outgoing messages**. Once configured, 
 you can set the `X-Email` header to [send messages via e-mail](publish.md#e-mail-notifications) (e.g. 
 `curl -d "hi there" -H "X-Email: phil@example.com" ntfy.sh/mytopic`).
 
@@ -44,13 +44,57 @@ As of today, only SMTP servers with PLAIN auth and STARTLS are supported. To ena
 following settings:
 
 * `base-url` is the root URL for the ntfy server; this is needed for e-mail footer
-* `smtp-addr` is the hostname:port of the SMTP server
-* `smtp-user` and `smtp-pass` are the username and password of the SMTP user
-* `smtp-from` is the e-mail address of the sender
+* `smtp-sender-addr` is the hostname:port of the SMTP server
+* `smtp-sender-user` and `smtp-sender-pass` are the username and password of the SMTP user
+* `smtp-sender-from` is the e-mail address of the sender
+
+Here's an example config using [Amazon SES](https://aws.amazon.com/ses/) for outgoing mail (this is how it is 
+configured for `ntfy.sh`):
+
+=== "/etc/ntfy/server.yml"
+    ``` yaml
+    base-url: "https://ntfy.sh"
+    smtp-sender-addr: "email-smtp.us-east-2.amazonaws.com:587"
+    smtp-sender-user: "AKIDEADBEEFAFFE12345"
+    smtp-sender-pass: "Abd13Kf+sfAk2DzifjafldkThisIsNotARealKeyOMG."
+    smtp-sender-from: "ntfy@ntfy.sh"
+    ```
 
 Please also refer to the [rate limiting](#rate-limiting) settings below, specifically `visitor-email-limit-burst` 
 and `visitor-email-limit-burst`. Setting these conservatively is necessary to avoid abuse.
 
+## E-mail publishing
+To allow publishing messages via e-mail, ntfy can run a lightweight **SMTP server for incoming messages**. Once configured, 
+users can [send emails to a topic e-mail address](publish.md#e-mail-publishing) (e.g. `mytopic@ntfy.sh` or 
+`myprefix-mytopic@ntfy.sh`) to publish messages to a topic. This is useful for e-mail based integrations such as for 
+statuspage.io (though these days most services also support webhooks and HTTP calls).
+
+To configure the SMTP server, you must at least set `smtp-server-listen` and `smtp-server-domain`:
+
+* `smtp-server-listen` defines the IP address and port the SMTP server will listen on, e.g. `:25` or `1.2.3.4:25`
+* `smtp-server-domain` is the e-mail domain, e.g. `ntfy.sh`
+* `smtp-server-addr-prefix` is an optional prefix for the e-mail addresses to prevent spam. If set to `ntfy-`, for instance,
+  only e-mails to `ntfy-$topic@ntfy.sh` will be accepted. If this is not set, all emails to `$topic@ntfy.sh` will be
+  accepted (which may obviously be a spam problem).
+
+Here's an example config (this is how it is configured for `ntfy.sh`):
+
+=== "/etc/ntfy/server.yml"
+    ``` yaml
+    smtp-server-listen: ":25"
+    smtp-server-domain: "ntfy.sh"
+    smtp-server-addr-prefix: "ntfy-"
+    ```
+
+In addition to configuring the ntfy server, you have to create two DNS records (an [MX record](https://en.wikipedia.org/wiki/MX_record) 
+and a corresponding A record), so incoming mail will find its way to your server. Here's an example of how `ntfy.sh` is 
+configured (in [Amazon Route 53](https://aws.amazon.com/route53/)):
+
+<figure markdown>
+  ![DNS records for incoming mail](static/img/screenshot-email-publishing-dns.png){ width=600 }
+  <figcaption>DNS records for incoming mail</figcaption>
+</figure>
+
 ## Behind a proxy (TLS, etc.)
 !!! warning
     If you are running ntfy behind a proxy, you must set the `behind-proxy` flag. Otherwise, all visitors are
@@ -66,7 +110,7 @@ as opposed to the remote IP address. If the `behind-proxy` flag is not set, all
 be counted as one, because from the perspective of the ntfy server, they all share the proxy's IP address.
 
 === "/etc/ntfy/server.yml"
-    ```
+    ``` yaml
     # Tell ntfy to use "X-Forwarded-For" to identify visitors
     behind-proxy: true
     ```

docs/install.md

@@ -26,21 +26,21 @@ deb/rpm packages.
 
 === "x86_64/amd64"
     ```bash
-    wget https://github.com/binwiederhier/ntfy/releases/download/v1.9.0/ntfy_1.9.0_linux_x86_64.tar.gz
+    wget https://github.com/binwiederhier/ntfy/releases/download/v1.10.0/ntfy_1.10.0_linux_x86_64.tar.gz
     sudo tar -C /usr/bin -zxf ntfy_*.tar.gz ntfy
     sudo ./ntfy serve
     ```
 
 === "armv7/armhf"
     ```bash
-    wget https://github.com/binwiederhier/ntfy/releases/download/v1.9.0/ntfy_1.9.0_linux_armv7.tar.gz
+    wget https://github.com/binwiederhier/ntfy/releases/download/v1.10.0/ntfy_1.10.0_linux_armv7.tar.gz
     sudo tar -C /usr/bin -zxf ntfy_*.tar.gz ntfy
     sudo ./ntfy serve
     ```
 
 === "arm64"
     ```bash
-    wget https://github.com/binwiederhier/ntfy/releases/download/v1.9.0/ntfy_1.9.0_linux_arm64.tar.gz
+    wget https://github.com/binwiederhier/ntfy/releases/download/v1.10.0/ntfy_1.10.0_linux_arm64.tar.gz
     sudo tar -C /usr/bin -zxf ntfy_*.tar.gz ntfy
     sudo ./ntfy serve
     ```
@@ -88,7 +88,7 @@ Manually installing the .deb file:
 
 === "x86_64/amd64"
     ```bash
-    wget https://github.com/binwiederhier/ntfy/releases/download/v1.9.0/ntfy_1.9.0_linux_amd64.deb
+    wget https://github.com/binwiederhier/ntfy/releases/download/v1.10.0/ntfy_1.10.0_linux_amd64.deb
     sudo dpkg -i ntfy_*.deb
     sudo systemctl enable ntfy
     sudo systemctl start ntfy
@@ -96,7 +96,7 @@ Manually installing the .deb file:
 
 === "armv7/armhf"
     ```bash
-    wget https://github.com/binwiederhier/ntfy/releases/download/v1.9.0/ntfy_1.9.0_linux_armv7.deb
+    wget https://github.com/binwiederhier/ntfy/releases/download/v1.10.0/ntfy_1.10.0_linux_armv7.deb
     sudo dpkg -i ntfy_*.deb
     sudo systemctl enable ntfy
     sudo systemctl start ntfy
@@ -104,7 +104,7 @@ Manually installing the .deb file:
 
 === "arm64"
     ```bash
-    wget https://github.com/binwiederhier/ntfy/releases/download/v1.9.0/ntfy_1.9.0_linux_arm64.deb
+    wget https://github.com/binwiederhier/ntfy/releases/download/v1.10.0/ntfy_1.10.0_linux_arm64.deb
     sudo dpkg -i ntfy_*.deb
     sudo systemctl enable ntfy
     sudo systemctl start ntfy
@@ -114,25 +114,39 @@ Manually installing the .deb file:
 
 === "x86_64/amd64"
     ```bash
-    sudo rpm -ivh https://github.com/binwiederhier/ntfy/releases/download/v1.9.0/ntfy_1.9.0_linux_amd64.rpm
+    sudo rpm -ivh https://github.com/binwiederhier/ntfy/releases/download/v1.10.0/ntfy_1.10.0_linux_amd64.rpm
     sudo systemctl enable ntfy 
     sudo systemctl start ntfy
     ```
 
 === "armv7/armhf"
     ```bash
-    sudo rpm -ivh https://github.com/binwiederhier/ntfy/releases/download/v1.9.0/ntfy_1.9.0_linux_armv7.rpm
+    sudo rpm -ivh https://github.com/binwiederhier/ntfy/releases/download/v1.10.0/ntfy_1.10.0_linux_armv7.rpm
     sudo systemctl enable ntfy 
     sudo systemctl start ntfy
     ```
 
 === "arm64"
     ```bash
-    sudo rpm -ivh https://github.com/binwiederhier/ntfy/releases/download/v1.9.0/ntfy_1.9.0_linux_arm64.rpm
+    sudo rpm -ivh https://github.com/binwiederhier/ntfy/releases/download/v1.10.0/ntfy_1.10.0_linux_arm64.rpm
     sudo systemctl enable ntfy 
     sudo systemctl start ntfy
     ```
 
+## Arch Linux
+ntfy can be installed using an [AUR package](https://aur.archlinux.org/packages/ntfysh-bin/). You can use an [AUR helper](https://wiki.archlinux.org/title/AUR_helpers) like `paru`, `yay` or others to download, build and install ntfy and keep it up to date.
+```
+paru -S ntfysh-bin
+```
+
+Alternatively, run the following commands to install ntfy manually:
+```
+curl https://aur.archlinux.org/cgit/aur.git/snapshot/ntfysh-bin.tar.gz | tar xzv
+cd ntfysh-bin
+makepkg -si
+```
+
+
 ## Docker
 The [ntfy image](https://hub.docker.com/r/binwiederhier/ntfy) is available for amd64, armv7 and arm64. It should be pretty
 straight forward to use.

docs/publish.md

@@ -691,6 +691,28 @@ Here's what that looks like in Google Mail:
   <figcaption>E-mail notification</figcaption>
 </figure>
 
+## E-mail publishing
+You can publish messages to a topic via e-mail, i.e. by sending an email to a specific address. For instance, you can
+publish a message to the topic `sometopic` by sending an e-mail to `ntfy-sometopic@ntfy.sh`. This is useful for e-mail 
+based integrations such as for statuspage.io (though these days most services also support webhooks and HTTP calls).
+
+Depending on the [server configuration](config.md#e-mail-publishing), the e-mail address format can have a prefix to 
+prevent spam on topics. For ntfy.sh, the prefix is configured to `ntfy-`, meaning that the general e-mail address 
+format is:
+
+```
+ntfy-$topic@ntfy.sh
+```
+
+As of today, e-mail publishing only supports adding a [message title](#message-title) (the e-mail subject). Tags, priority,
+delay and other features are not supported (yet). Here's an example that will publish a message with the 
+title `You've Got Mail` to topic `sometopic` (see [ntfy.sh/sometopic](https://ntfy.sh/sometopic)):
+
+<figure markdown>
+  ![e-mail publishing](static/img/screenshot-email-publishing-gmail.png){ width=500 }
+  <figcaption>Publishing a message via e-mail</figcaption>
+</figure>
+
 ## Advanced features
 
 ### Message caching
@@ -846,7 +868,7 @@ but just in case, let's list them all:
 |---|---|
 | **Message length** | Each message can be up to 512 bytes long. Longer messages are truncated. |
 | **Requests** | By default, the server is configured to allow 60 requests at once, and then refills the your allowed requests bucket at a rate of one request per 10 seconds. You can read more about this in the [rate limiting](config.md#rate-limiting) section. |
-| **E-mails** | By default, the server is configured to allow 16 e-mails at once, and then refills the your allowed e-mail bucket at a rate of one per hour. You can read more about this in the [rate limiting](config.md#rate-limiting) section. |
+| **E-mails** | By default, the server is configured to allow sending 16 e-mails at once, and then refills the your allowed e-mail bucket at a rate of one per hour. You can read more about this in the [rate limiting](config.md#rate-limiting) section. |
 | **Subscription limits** | By default, the server allows each visitor to keep 30 connections to the server open. |
 | **Total number of topics** | By default, the server is configured to allow 5,000 topics. The ntfy.sh server has higher limits though. |
 

go.mod

@@ -8,6 +8,7 @@ require (
 	firebase.google.com/go v3.13.0+incompatible
 	github.com/BurntSushi/toml v0.4.1 // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.1 // indirect
+	github.com/emersion/go-smtp v0.15.0
 	github.com/mattn/go-sqlite3 v1.14.9
 	github.com/olebedev/when v0.0.0-20211212231525-59bd4edcf9d6
 	github.com/stretchr/testify v1.7.0
@@ -26,6 +27,7 @@ require (
 	github.com/cncf/udpa/go v0.0.0-20210930031921-04548b0d99d4 // indirect
 	github.com/cncf/xds/go v0.0.0-20211130200136-a8f946100490 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21 // indirect
 	github.com/envoyproxy/go-control-plane v0.10.1 // indirect
 	github.com/envoyproxy/protoc-gen-validate v0.6.2 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect

go.sum

@@ -89,6 +89,10 @@ github.com/cpuguy83/go-md2man/v2 v2.0.1/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46t
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21 h1:OJyUGMJTzHTd1XQp98QTaHernxMYzRaOasRir9hUlFQ=
+github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21/go.mod h1:iL2twTeMvZnrg54ZoPDNfJaJaqy0xIQFuBdrLsmspwQ=
+github.com/emersion/go-smtp v0.15.0 h1:3+hMGMGrqP/lqd7qoxZc1hTU8LY8gHV9RFGWlqSDmP8=
+github.com/emersion/go-smtp v0.15.0/go.mod h1:qm27SGYgoIPRot6ubfQ/GpiPy/g3PaZAVRxiO/sDUgQ=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=

server/config.go

@@ -45,10 +45,13 @@ type Config struct {
 	ManagerInterval              time.Duration
 	AtSenderInterval             time.Duration
 	FirebaseKeepaliveInterval    time.Duration
-	SMTPAddr                     string
-	SMTPUser                     string
-	SMTPPass                     string
-	SMTPFrom                     string
+	SMTPSenderAddr               string
+	SMTPSenderUser               string
+	SMTPSenderPass               string
+	SMTPSenderFrom               string
+	SMTPServerListen             string
+	SMTPServerDomain             string
+	SMTPServerAddrPrefix         string
 	MessageLimit                 int
 	MinDelay                     time.Duration
 	MaxDelay                     time.Duration

server/index.gohtml

@@ -198,7 +198,7 @@
             curl -d "Backup failed" <span id="detailTopicUrl">ntfy.sh/topic</span>
         </code>
         <p id="detailNotificationsDisallowed">
-            If you'd like to receive desktop notifications when new messages arrive on this topic, you have
+            If you'd like to receive desktop notifications when new messages arrive on this topic, you have to
             <a href="#" onclick="return requestPermission()">grant the browser permission</a> to show notifications.
             Click the link to do so.
         </p>

server/server.go

@@ -5,9 +5,11 @@ import (
 	"context"
 	"embed"
 	"encoding/json"
+	"errors"
 	firebase "firebase.google.com/go"
 	"firebase.google.com/go/messaging"
 	"fmt"
+	"github.com/emersion/go-smtp"
 	"google.golang.org/api/option"
 	"heckel.io/ntfy/util"
 	"html/template"
@@ -15,6 +17,7 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"net/http/httptest"
 	"regexp"
 	"strconv"
 	"strings"
@@ -30,6 +33,8 @@ type Server struct {
 	config      *Config
 	httpServer  *http.Server
 	httpsServer *http.Server
+	smtpServer  *smtp.Server
+	smtpBackend *smtpBackend
 	topics      map[string]*topic
 	visitors    map[string]*visitor
 	firebase    subscriber
@@ -42,12 +47,19 @@ type Server struct {
 
 // errHTTP is a generic HTTP error for any non-200 HTTP error
 type errHTTP struct {
-	Code   int
-	Status string
+	Code     int    `json:"code,omitempty"`
+	HTTPCode int    `json:"http"`
+	Message  string `json:"error"`
+	Link     string `json:"link,omitempty"`
 }
 
 func (e errHTTP) Error() string {
-	return fmt.Sprintf("http: %s", e.Status)
+	return e.Message
+}
+
+func (e errHTTP) JSON() string {
+	b, _ := json.Marshal(&e)
+	return string(b)
 }
 
 type indexPage struct {
@@ -75,11 +87,12 @@ var (
 )
 
 var (
-	topicRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}$`) // Regex must match JS & Android app!
-	jsonRegex  = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/json$`)
-	sseRegex   = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/sse$`)
-	rawRegex   = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/raw$`)
-	sendRegex  = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/(publish|send|trigger)$`)
+	topicRegex       = regexp.MustCompile(`^[-_A-Za-z0-9]{1,64}$`)  // No /!
+	topicPathRegex   = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}$`) // Regex must match JS & Android app!
+	jsonPathRegex    = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/json$`)
+	ssePathRegex     = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/sse$`)
+	rawPathRegex     = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/raw$`)
+	publishPathRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/(publish|send|trigger)$`)
 
 	staticRegex      = regexp.MustCompile(`^/static/.+`)
 	docsRegex        = regexp.MustCompile(`^/docs(|/.*)$`)
@@ -104,9 +117,22 @@ var (
 	docsStaticFs     embed.FS
 	docsStaticCached = &util.CachingEmbedFS{ModTime: time.Now(), FS: docsStaticFs}
 
-	errHTTPBadRequest      = &errHTTP{http.StatusBadRequest, http.StatusText(http.StatusBadRequest)}
-	errHTTPNotFound        = &errHTTP{http.StatusNotFound, http.StatusText(http.StatusNotFound)}
-	errHTTPTooManyRequests = &errHTTP{http.StatusTooManyRequests, http.StatusText(http.StatusTooManyRequests)}
+	errHTTPNotFound                          = &errHTTP{40401, http.StatusNotFound, "page not found", ""}
+	errHTTPTooManyRequestsLimitRequests      = &errHTTP{42901, http.StatusTooManyRequests, "limit reached: too many requests, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
+	errHTTPTooManyRequestsLimitEmails        = &errHTTP{42902, http.StatusTooManyRequests, "limit reached: too many emails, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
+	errHTTPTooManyRequestsLimitSubscriptions = &errHTTP{42903, http.StatusTooManyRequests, "limit reached: too many active subscriptions, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
+	errHTTPTooManyRequestsLimitGlobalTopics  = &errHTTP{42904, http.StatusTooManyRequests, "limit reached: the total number of topics on the server has been reached, please contact the admin", "https://ntfy.sh/docs/publish/#limitations"}
+	errHTTPBadRequestEmailDisabled           = &errHTTP{40001, http.StatusBadRequest, "e-mail notifications are not enabled", "https://ntfy.sh/docs/config/#e-mail-notifications"}
+	errHTTPBadRequestDelayNoCache            = &errHTTP{40002, http.StatusBadRequest, "cannot disable cache for delayed message", ""}
+	errHTTPBadRequestDelayNoEmail            = &errHTTP{40003, http.StatusBadRequest, "delayed e-mail notifications are not supported", ""}
+	errHTTPBadRequestDelayCannotParse        = &errHTTP{40004, http.StatusBadRequest, "invalid delay parameter: unable to parse delay", "https://ntfy.sh/docs/publish/#scheduled-delivery"}
+	errHTTPBadRequestDelayTooSmall           = &errHTTP{40005, http.StatusBadRequest, "invalid delay parameter: too small, please refer to the docs", "https://ntfy.sh/docs/publish/#scheduled-delivery"}
+	errHTTPBadRequestDelayTooLarge           = &errHTTP{40006, http.StatusBadRequest, "invalid delay parameter: too large, please refer to the docs", "https://ntfy.sh/docs/publish/#scheduled-delivery"}
+	errHTTPBadRequestPriorityInvalid         = &errHTTP{40007, http.StatusBadRequest, "invalid priority parameter", "https://ntfy.sh/docs/publish/#message-priority"}
+	errHTTPBadRequestSinceInvalid            = &errHTTP{40008, http.StatusBadRequest, "invalid since parameter", "https://ntfy.sh/docs/subscribe/api/#fetch-cached-messages"}
+	errHTTPBadRequestTopicInvalid            = &errHTTP{40009, http.StatusBadRequest, "invalid topic: path invalid", ""}
+	errHTTPBadRequestTopicDisallowed         = &errHTTP{40010, http.StatusBadRequest, "invalid topic: topic name is disallowed", ""}
+	errHTTPInternalError                     = &errHTTP{50001, http.StatusInternalServerError, "internal server error", ""}
 )
 
 const (
@@ -126,8 +152,8 @@ func New(conf *Config) (*Server, error) {
 		}
 	}
 	var mailer mailer
-	if conf.SMTPAddr != "" {
-		mailer = &smtpMailer{config: conf}
+	if conf.SMTPSenderAddr != "" {
+		mailer = &smtpSender{config: conf}
 	}
 	cache, err := createCache(conf)
 	if err != nil {
@@ -202,6 +228,9 @@ func (s *Server) Run() error {
 	if s.config.ListenHTTPS != "" {
 		listenStr += fmt.Sprintf(" %s/https", s.config.ListenHTTPS)
 	}
+	if s.config.SMTPServerListen != "" {
+		listenStr += fmt.Sprintf(" %s/smtp", s.config.SMTPServerListen)
+	}
 	log.Printf("Listening on %s", listenStr)
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", s.handle)
@@ -218,10 +247,16 @@ func (s *Server) Run() error {
 			errChan <- s.httpsServer.ListenAndServeTLS(s.config.CertFile, s.config.KeyFile)
 		}()
 	}
+	if s.config.SMTPServerListen != "" {
+		go func() {
+			errChan <- s.runSMTPServer()
+		}()
+	}
 	s.mu.Unlock()
 	go s.runManager()
 	go s.runAtSender()
 	go s.runFirebaseKeepliver()
+
 	return <-errChan
 }
 
@@ -235,16 +270,24 @@ func (s *Server) Stop() {
 	if s.httpsServer != nil {
 		s.httpsServer.Close()
 	}
+	if s.smtpServer != nil {
+		s.smtpServer.Close()
+	}
 	close(s.closeChan)
 }
 
 func (s *Server) handle(w http.ResponseWriter, r *http.Request) {
 	if err := s.handleInternal(w, r); err != nil {
-		if e, ok := err.(*errHTTP); ok {
-			s.fail(w, r, e.Code, e)
-		} else {
-			s.fail(w, r, http.StatusInternalServerError, err)
+		var e *errHTTP
+		var ok bool
+		if e, ok = err.(*errHTTP); !ok {
+			e = errHTTPInternalError
 		}
+		log.Printf("[%s] %s - %d - %s", r.RemoteAddr, r.Method, e.HTTPCode, err.Error())
+		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
+		w.WriteHeader(e.HTTPCode)
+		io.WriteString(w, e.JSON()+"\n")
 	}
 }
 
@@ -261,17 +304,17 @@ func (s *Server) handleInternal(w http.ResponseWriter, r *http.Request) error {
 		return s.handleDocs(w, r)
 	} else if r.Method == http.MethodOptions {
 		return s.handleOptions(w, r)
-	} else if r.Method == http.MethodGet && topicRegex.MatchString(r.URL.Path) {
-		return s.handleHome(w, r)
-	} else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && topicRegex.MatchString(r.URL.Path) {
+	} else if r.Method == http.MethodGet && topicPathRegex.MatchString(r.URL.Path) {
+		return s.handleTopic(w, r)
+	} else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && topicPathRegex.MatchString(r.URL.Path) {
 		return s.withRateLimit(w, r, s.handlePublish)
-	} else if r.Method == http.MethodGet && sendRegex.MatchString(r.URL.Path) {
+	} else if r.Method == http.MethodGet && publishPathRegex.MatchString(r.URL.Path) {
 		return s.withRateLimit(w, r, s.handlePublish)
-	} else if r.Method == http.MethodGet && jsonRegex.MatchString(r.URL.Path) {
+	} else if r.Method == http.MethodGet && jsonPathRegex.MatchString(r.URL.Path) {
 		return s.withRateLimit(w, r, s.handleSubscribeJSON)
-	} else if r.Method == http.MethodGet && sseRegex.MatchString(r.URL.Path) {
+	} else if r.Method == http.MethodGet && ssePathRegex.MatchString(r.URL.Path) {
 		return s.withRateLimit(w, r, s.handleSubscribeSSE)
-	} else if r.Method == http.MethodGet && rawRegex.MatchString(r.URL.Path) {
+	} else if r.Method == http.MethodGet && rawPathRegex.MatchString(r.URL.Path) {
 		return s.withRateLimit(w, r, s.handleSubscribeRaw)
 	}
 	return errHTTPNotFound
@@ -284,6 +327,17 @@ func (s *Server) handleHome(w http.ResponseWriter, r *http.Request) error {
 	})
 }
 
+func (s *Server) handleTopic(w http.ResponseWriter, r *http.Request) error {
+	unifiedpush := readParam(r, "x-unifiedpush", "unifiedpush", "up") == "1" // see PUT/POST too!
+	if unifiedpush {
+		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
+		_, err := io.WriteString(w, `{"unifiedpush":{"version":1}}`+"\n")
+		return err
+	}
+	return s.handleHome(w, r)
+}
+
 func (s *Server) handleEmpty(_ http.ResponseWriter, _ *http.Request) error {
 	return nil
 }
@@ -314,17 +368,17 @@ func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visito
 		return err
 	}
 	m := newDefaultMessage(t.ID, strings.TrimSpace(string(b)))
-	cache, firebase, email, err := s.parseParams(r, m)
+	cache, firebase, email, err := s.parsePublishParams(r, m)
 	if err != nil {
 		return err
 	}
 	if email != "" {
 		if err := v.EmailAllowed(); err != nil {
-			return err
+			return errHTTPTooManyRequestsLimitEmails
 		}
 	}
 	if s.mailer == nil && email != "" {
-		return errHTTPBadRequest
+		return errHTTPBadRequestEmailDisabled
 	}
 	if m.Message == "" {
 		m.Message = emptyMessageBody
@@ -363,7 +417,7 @@ func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visito
 	return nil
 }
 
-func (s *Server) parseParams(r *http.Request, m *message) (cache bool, firebase bool, email string, err error) {
+func (s *Server) parsePublishParams(r *http.Request, m *message) (cache bool, firebase bool, email string, err error) {
 	cache = readParam(r, "x-cache", "cache") != "no"
 	firebase = readParam(r, "x-firebase", "firebase") != "no"
 	email = readParam(r, "x-email", "x-e-mail", "email", "e-mail", "mail", "e")
@@ -374,7 +428,7 @@ func (s *Server) parseParams(r *http.Request, m *message) (cache bool, firebase
 	}
 	m.Priority, err = util.ParsePriority(readParam(r, "x-priority", "priority", "prio", "p"))
 	if err != nil {
-		return false, false, "", errHTTPBadRequest
+		return false, false, "", errHTTPBadRequestPriorityInvalid
 	}
 	tagsStr := readParam(r, "x-tags", "tags", "tag", "ta")
 	if tagsStr != "" {
@@ -386,21 +440,25 @@ func (s *Server) parseParams(r *http.Request, m *message) (cache bool, firebase
 	delayStr := readParam(r, "x-delay", "delay", "x-at", "at", "x-in", "in")
 	if delayStr != "" {
 		if !cache {
-			return false, false, "", errHTTPBadRequest
+			return false, false, "", errHTTPBadRequestDelayNoCache
 		}
 		if email != "" {
-			return false, false, "", errHTTPBadRequest // we cannot store the email address (yet)
+			return false, false, "", errHTTPBadRequestDelayNoEmail // we cannot store the email address (yet)
 		}
 		delay, err := util.ParseFutureTime(delayStr, time.Now())
 		if err != nil {
-			return false, false, "", errHTTPBadRequest
+			return false, false, "", errHTTPBadRequestDelayCannotParse
 		} else if delay.Unix() < time.Now().Add(s.config.MinDelay).Unix() {
-			return false, false, "", errHTTPBadRequest
+			return false, false, "", errHTTPBadRequestDelayTooSmall
 		} else if delay.Unix() > time.Now().Add(s.config.MaxDelay).Unix() {
-			return false, false, "", errHTTPBadRequest
+			return false, false, "", errHTTPBadRequestDelayTooLarge
 		}
 		m.Time = delay.Unix()
 	}
+	unifiedpush := readParam(r, "x-unifiedpush", "unifiedpush", "up") == "1" // see GET too!
+	if unifiedpush {
+		firebase = false
+	}
 	return cache, firebase, email, nil
 }
 
@@ -456,8 +514,8 @@ func (s *Server) handleSubscribeRaw(w http.ResponseWriter, r *http.Request, v *v
 }
 
 func (s *Server) handleSubscribe(w http.ResponseWriter, r *http.Request, v *visitor, format string, contentType string, encoder messageEncoder) error {
-	if err := v.AddSubscription(); err != nil {
-		return errHTTPTooManyRequests
+	if err := v.SubscriptionAllowed(); err != nil {
+		return errHTTPTooManyRequestsLimitSubscriptions
 	}
 	defer v.RemoveSubscription()
 	topicsStr := strings.TrimSuffix(r.URL.Path[1:], "/"+format) // Hack
@@ -603,7 +661,7 @@ func parseSince(r *http.Request, poll bool) (sinceTime, error) {
 	} else if d, err := time.ParseDuration(since); err == nil {
 		return sinceTime(time.Now().Add(-1 * d)), nil
 	}
-	return sinceNoMessages, errHTTPBadRequest
+	return sinceNoMessages, errHTTPBadRequestSinceInvalid
 }
 
 func (s *Server) handleOptions(w http.ResponseWriter, _ *http.Request) error {
@@ -615,7 +673,7 @@ func (s *Server) handleOptions(w http.ResponseWriter, _ *http.Request) error {
 func (s *Server) topicFromPath(path string) (*topic, error) {
 	parts := strings.Split(path, "/")
 	if len(parts) < 2 {
-		return nil, errHTTPBadRequest
+		return nil, errHTTPBadRequestTopicInvalid
 	}
 	topics, err := s.topicsFromIDs(parts[1])
 	if err != nil {
@@ -630,11 +688,11 @@ func (s *Server) topicsFromIDs(ids ...string) ([]*topic, error) {
 	topics := make([]*topic, 0)
 	for _, id := range ids {
 		if util.InStringList(disallowedTopics, id) {
-			return nil, errHTTPBadRequest
+			return nil, errHTTPBadRequestTopicDisallowed
 		}
 		if _, ok := s.topics[id]; !ok {
 			if len(s.topics) >= s.config.GlobalTopicLimit {
-				return nil, errHTTPTooManyRequests
+				return nil, errHTTPTooManyRequestsLimitGlobalTopics
 			}
 			s.topics[id] = newTopic(id)
 		}
@@ -677,9 +735,44 @@ func (s *Server) updateStatsAndPrune() {
 		messages += msgs
 	}
 
+	// Mail stats
+	var mailSuccess, mailFailure int64
+	if s.smtpBackend != nil {
+		mailSuccess, mailFailure = s.smtpBackend.Counts()
+	}
+
 	// Print stats
-	log.Printf("Stats: %d message(s) published, %d topic(s) active, %d subscriber(s), %d message(s) buffered, %d visitor(s)",
-		s.messages, len(s.topics), subscribers, messages, len(s.visitors))
+	log.Printf("Stats: %d message(s) published, %d in cache, %d successful mails, %d failed, %d topic(s) active, %d subscriber(s), %d visitor(s)",
+		s.messages, messages, mailSuccess, mailFailure, len(s.topics), subscribers, len(s.visitors))
+}
+
+func (s *Server) runSMTPServer() error {
+	sub := func(m *message) error {
+		url := fmt.Sprintf("%s/%s", s.config.BaseURL, m.Topic)
+		req, err := http.NewRequest("PUT", url, strings.NewReader(m.Message))
+		if err != nil {
+			return err
+		}
+		if m.Title != "" {
+			req.Header.Set("Title", m.Title)
+		}
+		rr := httptest.NewRecorder()
+		s.handle(rr, req)
+		if rr.Code != http.StatusOK {
+			return errors.New("error: " + rr.Body.String())
+		}
+		return nil
+	}
+	s.smtpBackend = newMailBackend(s.config, sub)
+	s.smtpServer = smtp.NewServer(s.smtpBackend)
+	s.smtpServer.Addr = s.config.SMTPServerListen
+	s.smtpServer.Domain = s.config.SMTPServerDomain
+	s.smtpServer.ReadTimeout = 10 * time.Second
+	s.smtpServer.WriteTimeout = 10 * time.Second
+	s.smtpServer.MaxMessageBytes = 1024 * 1024 // Must be much larger than message size (headers, multipart, etc.)
+	s.smtpServer.MaxRecipients = 1
+	s.smtpServer.AllowInsecureAuth = true
+	return s.smtpServer.ListenAndServe()
 }
 
 func (s *Server) runManager() {
@@ -752,7 +845,7 @@ func (s *Server) sendDelayedMessages() error {
 func (s *Server) withRateLimit(w http.ResponseWriter, r *http.Request, handler func(w http.ResponseWriter, r *http.Request, v *visitor) error) error {
 	v := s.visitor(r)
 	if err := v.RequestAllowed(); err != nil {
-		return err
+		return errHTTPTooManyRequestsLimitRequests
 	}
 	return handler(w, r, v)
 }
@@ -784,9 +877,3 @@ func (s *Server) inc(counter *int64) {
 	defer s.mu.Unlock()
 	*counter++
 }
-
-func (s *Server) fail(w http.ResponseWriter, r *http.Request, code int, err error) {
-	log.Printf("[%s] %s - %d - %s", r.RemoteAddr, r.Method, code, err.Error())
-	w.WriteHeader(code)
-	_, _ = io.WriteString(w, fmt.Sprintf("%s\n", http.StatusText(code)))
-}

server/server.yml

@@ -1,7 +1,7 @@
 # ntfy server config file
 
 # Public facing base URL of the service (e.g. https://ntfy.sh or https://ntfy.example.com)
-# This setting is currently only used by the e-mail feature.
+# This setting is currently only used by the e-mail sending feature (outgoing mail only).
 #
 # base-url:
 
@@ -46,18 +46,32 @@
 #
 # behind-proxy: false
 
-# If enabled, allow e-mail notifications via the 'X-Email' header. As of today, only SMTP servers
-# with plain text auth and STARTLS are supported. Please also refer to the rate limiting settings
+# If enabled, allow outgoing e-mail notifications via the 'X-Email' header. If this header is set,
+# messages will additionally be sent out as e-mail using an external SMTP server. As of today, only
+# SMTP servers with plain text auth and STARTLS are supported. Please also refer to the rate limiting settings
 # below (visitor-email-limit-burst & visitor-email-limit-burst).
 #
-# - smtp-addr is the hostname:port of the SMTP server
-# - smtp-user/smtp-pass are the username and password of the SMTP user
-# - smtp-from is the e-mail address of the sender
+# - smtp-sender-addr is the hostname:port of the SMTP server
+# - smtp-sender-user/smtp-sender-pass are the username and password of the SMTP user
+# - smtp-sender-from is the e-mail address of the sender
 #
-# smtp-addr:
-# smtp-user:
-# smtp-pass:
-# smtp-from:
+# smtp-sender-addr:
+# smtp-sender-user:
+# smtp-sender-pass:
+# smtp-sender-from:
+
+# If enabled, ntfy will launch a lightweight SMTP server for incoming messages. Once configured, users can send
+# emails to a topic e-mail address to publish messages to a topic.
+#
+# - smtp-server-listen defines the IP address and port the SMTP server will listen on, e.g. :25 or 1.2.3.4:25
+# - smtp-server-domain is the e-mail domain, e.g. ntfy.sh
+# - smtp-server-addr-prefix is an optional prefix for the e-mail addresses to prevent spam. If set to "ntfy-",
+#   for instance, only e-mails to ntfy-$topic@ntfy.sh will be accepted. If this is not set, all emails to
+#   $topic@ntfy.sh will be accepted (which may obviously be a spam problem).
+#
+# smtp-server-listen:
+# smtp-server-domain:
+# smtp-server-addr-prefix:
 
 # Interval in which keepalive messages are sent to the client. This is to prevent
 # intermediaries closing the connection for inactivity.

server/server_test.go

@@ -252,6 +252,7 @@ func TestServer_PublishAtWithCacheError(t *testing.T) {
 		"In":    "30 min",
 	})
 	require.Equal(t, 400, response.Code)
+	require.Equal(t, errHTTPBadRequestDelayNoCache, toHTTPError(t, response.Body.String()))
 }
 
 func TestServer_PublishAtTooShortDelay(t *testing.T) {
@@ -582,6 +583,13 @@ func TestServer_PublishEmailNoMailer_Fail(t *testing.T) {
 	require.Equal(t, 400, response.Code)
 }
 
+func TestServer_UnifiedPushDiscovery(t *testing.T) {
+	s := newTestServer(t, newTestConfig(t))
+	response := request(t, s, "GET", "/mytopic?up=1", "", nil)
+	require.Equal(t, 200, response.Code)
+	require.Equal(t, `{"unifiedpush":{"version":1}}`+"\n", response.Body.String())
+}
+
 func newTestConfig(t *testing.T) *Config {
 	conf := NewConfig()
 	conf.CacheFile = filepath.Join(t.TempDir(), "cache.db")
@@ -644,6 +652,12 @@ func toMessage(t *testing.T, s string) *message {
 	return &m
 }
 
+func toHTTPError(t *testing.T, s string) *errHTTP {
+	var e errHTTP
+	require.Nil(t, json.NewDecoder(strings.NewReader(s)).Decode(&e))
+	return &e
+}
+
 func firebaseServiceAccountFile(t *testing.T) string {
 	if os.Getenv("NTFY_TEST_FIREBASE_SERVICE_ACCOUNT_FILE") != "" {
 		return os.Getenv("NTFY_TEST_FIREBASE_SERVICE_ACCOUNT_FILE")

server/smtp_sender.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"heckel.io/ntfy/util"
+	"mime"
 	"net"
 	"net/smtp"
 	"strings"
@@ -15,21 +16,21 @@ type mailer interface {
 	Send(from, to string, m *message) error
 }
 
-type smtpMailer struct {
+type smtpSender struct {
 	config *Config
 }
 
-func (s *smtpMailer) Send(senderIP, to string, m *message) error {
-	host, _, err := net.SplitHostPort(s.config.SMTPAddr)
+func (s *smtpSender) Send(senderIP, to string, m *message) error {
+	host, _, err := net.SplitHostPort(s.config.SMTPSenderAddr)
 	if err != nil {
 		return err
 	}
-	message, err := formatMail(s.config.BaseURL, senderIP, s.config.SMTPFrom, to, m)
+	message, err := formatMail(s.config.BaseURL, senderIP, s.config.SMTPSenderFrom, to, m)
 	if err != nil {
 		return err
 	}
-	auth := smtp.PlainAuth("", s.config.SMTPUser, s.config.SMTPPass, host)
-	return smtp.SendMail(s.config.SMTPAddr, auth, s.config.SMTPFrom, []string{to}, []byte(message))
+	auth := smtp.PlainAuth("", s.config.SMTPSenderUser, s.config.SMTPSenderPass, host)
+	return smtp.SendMail(s.config.SMTPSenderAddr, auth, s.config.SMTPSenderFrom, []string{to}, []byte(message))
 }
 
 func formatMail(baseURL, senderIP, from, to string, m *message) (string, error) {
@@ -66,10 +67,11 @@ func formatMail(baseURL, senderIP, from, to string, m *message) (string, error)
 	if trailer != "" {
 		message += "\n\n" + trailer
 	}
-	body := `Content-Type: text/plain; charset="utf-8"
-From: "{shortTopicURL}" <{from}>
+	subject = mime.BEncoding.Encode("utf-8", subject)
+	body := `From: "{shortTopicURL}" <{from}>
 To: {to}
 Subject: {subject}
+Content-Type: text/plain; charset="utf-8"
 
 {message}
 

server/smtp_sender_test.go

@@ -13,10 +13,10 @@ func TestFormatMail_Basic(t *testing.T) {
 		Topic:   "alerts",
 		Message: "A simple message",
 	})
-	expected := `Content-Type: text/plain; charset="utf-8"
-From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
+	expected := `From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
 To: phil@example.com
 Subject: A simple message
+Content-Type: text/plain; charset="utf-8"
 
 A simple message
 
@@ -34,10 +34,10 @@ func TestFormatMail_JustEmojis(t *testing.T) {
 		Message: "A simple message",
 		Tags:    []string{"grinning"},
 	})
-	expected := `Content-Type: text/plain; charset="utf-8"
-From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
+	expected := `From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
 To: phil@example.com
-Subject: 😀 A simple message
+Subject: =?utf-8?b?8J+YgCBBIHNpbXBsZSBtZXNzYWdl?=
+Content-Type: text/plain; charset="utf-8"
 
 A simple message
 
@@ -55,10 +55,10 @@ func TestFormatMail_JustOtherTags(t *testing.T) {
 		Message: "A simple message",
 		Tags:    []string{"not-an-emoji"},
 	})
-	expected := `Content-Type: text/plain; charset="utf-8"
-From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
+	expected := `From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
 To: phil@example.com
 Subject: A simple message
+Content-Type: text/plain; charset="utf-8"
 
 A simple message
 
@@ -78,10 +78,10 @@ func TestFormatMail_JustPriority(t *testing.T) {
 		Message:  "A simple message",
 		Priority: 2,
 	})
-	expected := `Content-Type: text/plain; charset="utf-8"
-From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
+	expected := `From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
 To: phil@example.com
 Subject: A simple message
+Content-Type: text/plain; charset="utf-8"
 
 A simple message
 
@@ -101,10 +101,10 @@ func TestFormatMail_UTF8Subject(t *testing.T) {
 		Message: "A simple message",
 		Title:   " :: A not so simple title öäüß ¡Hola, señor!",
 	})
-	expected := `Content-Type: text/plain; charset="utf-8"
-From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
+	expected := `From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
 To: phil@example.com
-Subject:  :: A not so simple title öäüß ¡Hola, señor!
+Subject: =?utf-8?b?IDo6IEEgbm90IHNvIHNpbXBsZSB0aXRsZSDDtsOkw7zDnyDCoUhvbGEsIHNl?= =?utf-8?b?w7FvciE=?=
+Content-Type: text/plain; charset="utf-8"
 
 A simple message
 
@@ -124,10 +124,10 @@ func TestFormatMail_WithAllTheThings(t *testing.T) {
 		Title:    "Oh no 🙈\nThis is a message across\nmultiple lines",
 		Message:  "A message that contains monkeys 🙉\nNo really, though. Monkeys!",
 	})
-	expected := `Content-Type: text/plain; charset="utf-8"
-From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
+	expected := `From: "ntfy.sh/alerts" <ntfy@ntfy.sh>
 To: phil@example.com
-Subject: ⚠️ 💀 Oh no 🙈 This is a message across multiple lines
+Subject: =?utf-8?b?4pqg77iPIPCfkoAgT2ggbm8g8J+ZiCBUaGlzIGlzIGEgbWVzc2FnZSBhY3Jv?= =?utf-8?b?c3MgbXVsdGlwbGUgbGluZXM=?=
+Content-Type: text/plain; charset="utf-8"
 
 A message that contains monkeys 🙉
 No really, though. Monkeys!

server/smtp_server.go

@@ -0,0 +1,195 @@
+package server
+
+import (
+	"bytes"
+	"errors"
+	"github.com/emersion/go-smtp"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/mail"
+	"strings"
+	"sync"
+)
+
+var (
+	errInvalidDomain          = errors.New("invalid domain")
+	errInvalidAddress         = errors.New("invalid address")
+	errInvalidTopic           = errors.New("invalid topic")
+	errTooManyRecipients      = errors.New("too many recipients")
+	errUnsupportedContentType = errors.New("unsupported content type")
+)
+
+// smtpBackend implements SMTP server methods.
+type smtpBackend struct {
+	config  *Config
+	sub     subscriber
+	success int64
+	failure int64
+	mu      sync.Mutex
+}
+
+func newMailBackend(conf *Config, sub subscriber) *smtpBackend {
+	return &smtpBackend{
+		config: conf,
+		sub:    sub,
+	}
+}
+
+func (b *smtpBackend) Login(state *smtp.ConnectionState, username, password string) (smtp.Session, error) {
+	return &smtpSession{backend: b}, nil
+}
+
+func (b *smtpBackend) AnonymousLogin(state *smtp.ConnectionState) (smtp.Session, error) {
+	return &smtpSession{backend: b}, nil
+}
+
+func (b *smtpBackend) Counts() (success int64, failure int64) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	return b.success, b.failure
+}
+
+// smtpSession is returned after EHLO.
+type smtpSession struct {
+	backend *smtpBackend
+	topic   string
+	mu      sync.Mutex
+}
+
+func (s *smtpSession) AuthPlain(username, password string) error {
+	return nil
+}
+
+func (s *smtpSession) Mail(from string, opts smtp.MailOptions) error {
+	return nil
+}
+
+func (s *smtpSession) Rcpt(to string) error {
+	return s.withFailCount(func() error {
+		conf := s.backend.config
+		addressList, err := mail.ParseAddressList(to)
+		if err != nil {
+			return err
+		} else if len(addressList) != 1 {
+			return errTooManyRecipients
+		}
+		to = addressList[0].Address
+		if !strings.HasSuffix(to, "@"+conf.SMTPServerDomain) {
+			return errInvalidDomain
+		}
+		to = strings.TrimSuffix(to, "@"+conf.SMTPServerDomain)
+		if conf.SMTPServerAddrPrefix != "" {
+			if !strings.HasPrefix(to, conf.SMTPServerAddrPrefix) {
+				return errInvalidAddress
+			}
+			to = strings.TrimPrefix(to, conf.SMTPServerAddrPrefix)
+		}
+		if !topicRegex.MatchString(to) {
+			return errInvalidTopic
+		}
+		s.mu.Lock()
+		s.topic = to
+		s.mu.Unlock()
+		return nil
+	})
+}
+
+func (s *smtpSession) Data(r io.Reader) error {
+	return s.withFailCount(func() error {
+		conf := s.backend.config
+		b, err := io.ReadAll(r) // Protected by MaxMessageBytes
+		if err != nil {
+			return err
+		}
+		msg, err := mail.ReadMessage(bytes.NewReader(b))
+		if err != nil {
+			return err
+		}
+		body, err := readMailBody(msg)
+		if err != nil {
+			return err
+		}
+		body = strings.TrimSpace(body)
+		if len(body) > conf.MessageLimit {
+			body = body[:conf.MessageLimit]
+		}
+		m := newDefaultMessage(s.topic, body)
+		subject := strings.TrimSpace(msg.Header.Get("Subject"))
+		if subject != "" {
+			dec := mime.WordDecoder{}
+			subject, err := dec.DecodeHeader(subject)
+			if err != nil {
+				return err
+			}
+			m.Title = subject
+		}
+		if m.Title != "" && m.Message == "" {
+			m.Message = m.Title // Flip them, this makes more sense
+			m.Title = ""
+		}
+		if err := s.backend.sub(m); err != nil {
+			return err
+		}
+		s.backend.mu.Lock()
+		s.backend.success++
+		s.backend.mu.Unlock()
+		return nil
+	})
+}
+
+func (s *smtpSession) Reset() {
+	s.mu.Lock()
+	s.topic = ""
+	s.mu.Unlock()
+}
+
+func (s *smtpSession) Logout() error {
+	return nil
+}
+
+func (s *smtpSession) withFailCount(fn func() error) error {
+	err := fn()
+	s.backend.mu.Lock()
+	defer s.backend.mu.Unlock()
+	if err != nil {
+		s.backend.failure++
+	}
+	return err
+}
+
+func readMailBody(msg *mail.Message) (string, error) {
+	contentType, params, err := mime.ParseMediaType(msg.Header.Get("Content-Type"))
+	if err != nil {
+		return "", err
+	}
+	if contentType == "text/plain" {
+		body, err := io.ReadAll(msg.Body)
+		if err != nil {
+			return "", err
+		}
+		return string(body), nil
+	}
+	if strings.HasPrefix(contentType, "multipart/") {
+		mr := multipart.NewReader(msg.Body, params["boundary"])
+		for {
+			part, err := mr.NextPart()
+			if err != nil { // may be io.EOF
+				return "", err
+			}
+			partContentType, _, err := mime.ParseMediaType(part.Header.Get("Content-Type"))
+			if err != nil {
+				return "", err
+			}
+			if partContentType != "text/plain" {
+				continue
+			}
+			body, err := io.ReadAll(part)
+			if err != nil {
+				return "", err
+			}
+			return string(body), nil
+		}
+	}
+	return "", errUnsupportedContentType
+}

server/smtp_server_test.go

@@ -0,0 +1,190 @@
+package server
+
+import (
+	"github.com/emersion/go-smtp"
+	"github.com/stretchr/testify/require"
+	"strings"
+	"testing"
+)
+
+func TestSmtpBackend_Multipart(t *testing.T) {
+	email := `MIME-Version: 1.0
+Date: Tue, 28 Dec 2021 00:30:10 +0100
+Message-ID: <CAAvm79YP0C=Rt1N=KWmSUBB87KK2rRChmdzKqF1vCwMEUiVzLQ@mail.gmail.com>
+Subject: and one more
+From: Phil <phil@example.com>
+To: ntfy-mytopic@ntfy.sh
+Content-Type: multipart/alternative; boundary="000000000000f3320b05d42915c9"
+
+--000000000000f3320b05d42915c9
+Content-Type: text/plain; charset="UTF-8"
+
+what's up
+
+--000000000000f3320b05d42915c9
+Content-Type: text/html; charset="UTF-8"
+
+<div dir="ltr">what&#39;s up<br clear="all"><div><br></div></div>
+
+--000000000000f3320b05d42915c9--`
+	_, backend := newTestBackend(t, func(m *message) error {
+		require.Equal(t, "mytopic", m.Topic)
+		require.Equal(t, "and one more", m.Title)
+		require.Equal(t, "what's up", m.Message)
+		return nil
+	})
+	session, _ := backend.AnonymousLogin(nil)
+	require.Nil(t, session.Mail("phil@example.com", smtp.MailOptions{}))
+	require.Nil(t, session.Rcpt("ntfy-mytopic@ntfy.sh"))
+	require.Nil(t, session.Data(strings.NewReader(email)))
+}
+
+func TestSmtpBackend_MultipartNoBody(t *testing.T) {
+	email := `MIME-Version: 1.0
+Date: Tue, 28 Dec 2021 01:33:34 +0100
+Message-ID: <CAAvm7ABCDsi9vsuu0WTRXzZQBC8dXrDOLT8iCWdqrsmg@mail.gmail.com>
+Subject: This email has a subject but no body
+From: Phil <phil@example.com>
+To: ntfy-emailtest@ntfy.sh
+Content-Type: multipart/alternative; boundary="000000000000bcf4a405d429f8d4"
+
+--000000000000bcf4a405d429f8d4
+Content-Type: text/plain; charset="UTF-8"
+
+
+
+--000000000000bcf4a405d429f8d4
+Content-Type: text/html; charset="UTF-8"
+
+<div dir="ltr"><br></div>
+
+--000000000000bcf4a405d429f8d4--`
+	_, backend := newTestBackend(t, func(m *message) error {
+		require.Equal(t, "emailtest", m.Topic)
+		require.Equal(t, "", m.Title) // We flipped message and body
+		require.Equal(t, "This email has a subject but no body", m.Message)
+		return nil
+	})
+	session, _ := backend.AnonymousLogin(nil)
+	require.Nil(t, session.Mail("phil@example.com", smtp.MailOptions{}))
+	require.Nil(t, session.Rcpt("ntfy-emailtest@ntfy.sh"))
+	require.Nil(t, session.Data(strings.NewReader(email)))
+}
+
+func TestSmtpBackend_Plaintext(t *testing.T) {
+	email := `Date: Tue, 28 Dec 2021 00:30:10 +0100
+Message-ID: <CAAvm79YP0C=Rt1N=KWmSUBB87KK2rRChmdzKqF1vCwMEUiVzLQ@mail.gmail.com>
+Subject: and one more
+From: Phil <phil@example.com>
+To: mytopic@ntfy.sh
+Content-Type: text/plain; charset="UTF-8"
+
+what's up
+`
+	conf, backend := newTestBackend(t, func(m *message) error {
+		require.Equal(t, "mytopic", m.Topic)
+		require.Equal(t, "and one more", m.Title)
+		require.Equal(t, "what's up", m.Message)
+		return nil
+	})
+	conf.SMTPServerAddrPrefix = ""
+	session, _ := backend.AnonymousLogin(nil)
+	require.Nil(t, session.Mail("phil@example.com", smtp.MailOptions{}))
+	require.Nil(t, session.Rcpt("mytopic@ntfy.sh"))
+	require.Nil(t, session.Data(strings.NewReader(email)))
+}
+
+func TestSmtpBackend_Plaintext_EncodedSubject(t *testing.T) {
+	email := `Date: Tue, 28 Dec 2021 00:30:10 +0100
+Subject: =?UTF-8?B?VGhyZWUgc2FudGFzIPCfjoXwn46F8J+OhQ==?=
+From: Phil <phil@example.com>
+To: ntfy-mytopic@ntfy.sh
+Content-Type: text/plain; charset="UTF-8"
+
+what's up
+`
+	_, backend := newTestBackend(t, func(m *message) error {
+		require.Equal(t, "Three santas 🎅🎅🎅", m.Title)
+		return nil
+	})
+	session, _ := backend.AnonymousLogin(nil)
+	require.Nil(t, session.Mail("phil@example.com", smtp.MailOptions{}))
+	require.Nil(t, session.Rcpt("ntfy-mytopic@ntfy.sh"))
+	require.Nil(t, session.Data(strings.NewReader(email)))
+}
+
+func TestSmtpBackend_Plaintext_TooLongTruncate(t *testing.T) {
+	email := `Date: Tue, 28 Dec 2021 00:30:10 +0100
+Message-ID: <CAAvm79YP0C=Rt1N=KWmSUBB87KK2rRChmdzKqF1vCwMEUiVzLQ@mail.gmail.com>
+Subject: and one more
+From: Phil <phil@example.com>
+To: mytopic@ntfy.sh
+Content-Type: text/plain; charset="UTF-8"
+
+you know this is a string.
+it's a long string. 
+it's supposed to be longer than the max message length
+which is 512 bytes,
+which some people say is too short
+but it kinda makes sense when you look at what it looks like one a phone
+heck this wasn't even half of it so far.
+so i'm gonna fill the rest of this with AAAAAAAAAAAAAAAAAAAAAAAAAAA
+AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
+AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAa
+AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
+and with BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
+BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
+BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
+that should do it
+`
+	conf, backend := newTestBackend(t, func(m *message) error {
+		expected := `you know this is a string.
+it's a long string. 
+it's supposed to be longer than the max message length
+which is 512 bytes,
+which some people say is too short
+but it kinda makes sense when you look at what it looks like one a phone
+heck this wasn't even half of it so far.
+so i'm gonna fill the rest of this with AAAAAAAAAAAAAAAAAAAAAAAAAAA
+AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
+AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAa
+AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
+and with `
+		require.Equal(t, expected, m.Message)
+		return nil
+	})
+	conf.SMTPServerAddrPrefix = ""
+	session, _ := backend.AnonymousLogin(nil)
+	require.Nil(t, session.Mail("phil@example.com", smtp.MailOptions{}))
+	require.Nil(t, session.Rcpt("mytopic@ntfy.sh"))
+	require.Nil(t, session.Data(strings.NewReader(email)))
+}
+
+func TestSmtpBackend_Unsupported(t *testing.T) {
+	email := `Date: Tue, 28 Dec 2021 00:30:10 +0100
+Message-ID: <CAAvm79YP0C=Rt1N=KWmSUBB87KK2rRChmdzKqF1vCwMEUiVzLQ@mail.gmail.com>
+Subject: and one more
+From: Phil <phil@example.com>
+To: mytopic@ntfy.sh
+Content-Type: text/SOMETHINGELSE
+
+what's up
+`
+	conf, backend := newTestBackend(t, func(m *message) error {
+		return nil
+	})
+	conf.SMTPServerAddrPrefix = ""
+	session, _ := backend.Login(nil, "user", "pass")
+	require.Nil(t, session.Mail("phil@example.com", smtp.MailOptions{}))
+	require.Nil(t, session.Rcpt("mytopic@ntfy.sh"))
+	require.Equal(t, errUnsupportedContentType, session.Data(strings.NewReader(email)))
+}
+
+func newTestBackend(t *testing.T, sub subscriber) (*Config, *smtpBackend) {
+	conf := newTestConfig(t)
+	conf.SMTPServerListen = ":25"
+	conf.SMTPServerDomain = "ntfy.sh"
+	conf.SMTPServerAddrPrefix = "ntfy-"
+	backend := newMailBackend(conf, sub)
+	return conf, backend
+}

server/visitor.go

@@ -1,6 +1,7 @@
 package server
 
 import (
+	"errors"
 	"golang.org/x/time/rate"
 	"heckel.io/ntfy/util"
 	"sync"
@@ -14,6 +15,10 @@ const (
 	visitorExpungeAfter = 24 * time.Hour
 )
 
+var (
+	errVisitorLimitReached = errors.New("limit reached")
+)
+
 // visitor represents an API user, and its associated rate.Limiter used for rate limiting
 type visitor struct {
 	config        *Config
@@ -42,23 +47,23 @@ func (v *visitor) IP() string {
 
 func (v *visitor) RequestAllowed() error {
 	if !v.requests.Allow() {
-		return errHTTPTooManyRequests
+		return errVisitorLimitReached
 	}
 	return nil
 }
 
 func (v *visitor) EmailAllowed() error {
 	if !v.emails.Allow() {
-		return errHTTPTooManyRequests
+		return errVisitorLimitReached
 	}
 	return nil
 }
 
-func (v *visitor) AddSubscription() error {
+func (v *visitor) SubscriptionAllowed() error {
 	v.mu.Lock()
 	defer v.mu.Unlock()
 	if err := v.subscriptions.Add(1); err != nil {
-		return errHTTPTooManyRequests
+		return errVisitorLimitReached
 	}
 	return nil
 }