moriyoshi/dev-mta-postfix repository overview

⁠dev-mta-postfix

A simple MTA for development using Postfix

⁠Features

• Catch-all email address

  Any mails to arbitrary senders can be directed to a single e-mail address

• Gmail XOAUTH2 support

  Thanks to cyrus-sasl-xoauth2⁠, SASL XOAuth2 authentication is supported out of the box.

⁠Synopsis

docker run \
  -e [email protected] \
  -e POSTFIX_RELAY_HOST='[smtp.gmail.com]:587' \
  -e POSTFIX_RELAY_TLS=may \
  -e [email protected] \
  -e POSTFIX_RELAY_AUTH_PASSWORD=credential-such-as-XOAUTH2-token \
  moriyoshi/dev-mta-postfix

⁠Environment variables

• CATCHALL_EMAIL_ADDRESS

  -e [email protected]
  

  Copy

• POSTFIX_RELAY_HOST

  -e POSTFIX_RELAY_HOST='[smtp.gmail.com]:587'
  

  Copy

• POSTFIX_RELAY_TLS

  -e POSTFIX_RELAY_TLS=may
  

  Copy

• POSTFIX_RELAY_AUTH_USER

  -e [email protected]
  

  Copy

• POSTFIX_RELAY_AUTH_PASSWORD

  -e POSTFIX_RELAY_AUTH_PASSWORD=credential-such-as-XOAUTH2-token
  

  Copy

• POSTFIX_RELAY_HOST_BY_SENDER

  -e POSTFIX_RELAY_HOST_BY_SENDER='
  [email protected]	[smtp.gmail.com]:587
  [email protected]	[intranet]:25
  '
  

  Copy

• POSTFIX_RELAY_SASL_MECHANISMS

  -e POSTFIX_RELAY_SASL_MECHANISMS=login,plain
  

  Copy

  -e POSTFIX_RELAY_SASL_MECHANISMS=xoauth2
  

  Copy

• POSTFIX_ALIASES

  -e POSTFIX_ALIASES='
  localuser	root
  do_something	|command
  '
  

  Copy

• OAUTH2_TOKEN_AUTO_REFRESH

  -e OAUTH2_TOKEN_AUTO_REFRESH=1
  

  Copy

  Setting a non-empty value enables OAuth2 token auto-refresh.

⁠OAuth2 token auto refreshing

Executing the following outputs the OAuth2 authorization endpoint URL.

docker run \
  --rm \
  -e OAUTH2_AUTH_ENDPOINT=https://accounts.google.com/o/oauth2/auth \
  -e OAUTH2_TOKEN_ENDPOINT=https://accounts.google.com/o/oauth2/token \
  -e OAUTH2_SCOPE=https://mail.google.com/ \
  -e OAUTH2_CLIENT_ID=***** \
  -e OAUTH2_CLIENT_SECRET=***** \
  -v SOME-DIRECTORY:/dev-mta-postfix/state \
  moriyoshi/dev-mta-postfix auth

Get the authorization code by navigating your browser to the URL and put the code to the [oauth2-state] in SOME-DIRECTORY/state.ini that should have been created by the above.

[oauth2]
client_id = *****
client_secret = *****

[oauth2-state]
authorization_code = HERE

Then, launch the container like below.

docker run \
  -e [email protected] \
  -e POSTFIX_RELAY_HOST='[smtp.gmail.com]:587' \
  -e POSTFIX_RELAY_TLS=may \
  -e [email protected] \
  -e OAUTH2_TOKEN_AUTO_REFRESH=1 \
  -v SOME-DIRECTORY:/dev-mta-postfix/state \
  moriyoshi/dev-mta-postfix

⁠License

The source codes that originate from this repository are solely licensed under the MIT license.

Other copyrighted materials may be licensed under the different terms.