smtp2mqtt

Simple SMTP to MQTT relay/forwarder.

Ever wanted to just forward your alert e-mails to MQTT? smtp2mqtt can do it.

Features

• Single executable (thanks to Go!)
• Linux/Windows/Mac/BSD support
• multipart text/html e-mails supported
• (optional) JSON support

Examples

Here is quick example, just to get idea what you can do with it.

Quick Examples

Start server:

$ ./smtp2mqtt -listen 0.0.0.0:10025
2019/10/22 21:51:25 Listening on: 0.0.0.0:10025

Run SMTP server forwarder and forward to MQTT 192.168.1.1 in JSON:

$ ./smtp2mqtt -json -topic smtp/ -mqtt tcp://192.168.1.1:1883
2019/10/22 21:52:25 Listening on: 0.0.0.0:10025

Download

You can find binary and source releases on Github under "Releases". Here's the link to the latest release

Options explained

$ ./smtp2mqtt
Usage of ./smtp2mqtt:
  -allow string
    	Allow only specific IPs to send e-mail (e.g. 192.168.1.)
  -debug
    	Enable debug messages
  -deny string
    	Deny specific IPs to send e-mail (e.g. 192.168.1.10)
  -json
    	post to MQTT topic as json
  -keep
    	keep connection to MQTT
  -listen string
    	Listen on specific IP and port (default "0.0.0.0:10025")
  -mqtt string
    	connect to specified MQTT server (default "tcp://127.0.0.1:1883")
  -password string
    	MQTT password for connecting
  -topic string
    	prepend specified string to MQTT topic (e.g. 'smtp/')
  -user string
    	MQTT username for connecting
  -version
    	Display version
  -welcome string
    	Welcome message for SMTP session (default "MQTT-forwarder ESMTP ready.")

Building

Linux/Mac/POSIX builds

Just type:

go build

Static compiling:

CGO_ENABLED=0 go build -ldflags "-extldflags -static"

Windows builds

Just type:

go build

ToDo

• Implement TLS support for MQTT

Done

• Implement JSON support

Credits

Vlatko Kosturjak