command module
Version: v0.6.1 Latest Latest

This package is not in the latest version of its module.

Go to latest
Published: Feb 13, 2020 License: GPL-3.0 Imports: 26 Imported by: 0



This Go program is a SMTP-proxy that DKIM-signs e-mails before submission to an upstream SMTP-server.

Build Status GoDoc Go Report Card


Special thanks to @emersion for creating and providing the following Go libraries that are the main building blocks of this program:

Additional dependencies are the following awesome Go libraries:


You basically have two options to install this Go program package:

  1. If you have Go installed and configured on your PATH, just do the following go get inside your GOPATH to get the latest version:
go get -u
  1. If you do not have Go installed and just want to use a released binary, then you can just go ahead and download a pre-compiled Linux amd64 binary from the Github releases.

Finally put the smtp-dkim-signer binary onto your PATH and make sure it is executable.


The following YAML file is an example configuration with one virtual host:

Address: "localhost:25"
Domain: "localhost"
  Agreed: true
  Contact: your-name@your-domain.tld
  Challenge: http
  ChallengePort: 80
  - Domain: your-domain.tld
    Upstream: "your-upstream-smtp:465"
    Selector: "your-dkim-selector"
    PrivKeyPath: "your-private-key-file" OR |
    HeaderCan: "relaxed"
    BodyCan: "simple"
  - "From"
  - "Reply-To"
  - "Subject"
  - "Date"
  - "To"
  - "Cc"
  - "In-Reply-To"
  - "References"
  - "Message-ID"
  - "Resent-Date"
  - "Resent-From"
  - "Resent-To"
  - "Resent-Cc"
# optional:
  AccessToken: "your-rollbar-access-token"
  Environment: production

Save this file in one of the following locations and run ./smtp-dkim-signer:

  • /etc/smtp-dkim-signer/smtp-dkim-signer.yaml
  • $HOME/.smtp-dkim-signer.yaml
  • $PWD/smtp-dkim-signer.yaml


Copyright (C) 2018 - 2020, Marc Hoersken

This software is licensed as described in the file LICENSE, which you should have received as part of this software distribution.

All trademarks are the property of their respective owners.


The Go Gopher

There is no documentation for this package.

Jump to

Keyboard shortcuts

? : This menu
/ : Search site
f or F : Jump to
y or Y : Canonical URL