postfix-mysql

Proof of concept of using Mysql to store SASL users and allowed sender domains.

Moving parts

• Postfix
• Cyrus SASL library
• Mysql as a storage for users configuration

Known issues

• Mysql IP has to be used, hostname does not work (Cyrus seem to treat it as socket name rather than hostname)

(Manually) tested scenarios

• Auth: user unable to send a email not using auth
• Auth: user unable to auth using incorrect username or password
• Auth: user able to auth using username & password from the Mysql table containing users
• Sender: user allowed to send mail only as *@example.com can send an email from test@example.com
• Sender: user allowed to send mail only as *@example.com can not send an email from test@mail.example.com
• Sender: user allowed to send mail as *@example.net and *@mail.example.net can send an email from test@example.net and test@mail.example.net
• Sender: user allowed to send mail as test@gmail.com can send an email from test@gmail.com
• Sender: user allowed to send mail as test@gmail.com can NOT send emails from any other address

Helpful commands

# Look up sender in sender map
postmap -q john@example.com mysql:/etc/postfix/virt/senders.cf

# Get SASL config
saslfinger -s

-- Enable sql log to see what queries Postfix is making
SET global log_output = 'FILE';
SET global general_log_file='/var/log/mysql/general.log';
SET global general_log = 1;