Tests for CI (mostly implemented in `tests/tests.sh`)

[lpoujade]

For the most part, can be implemented in php, using smtptest to send mail and mailpit api to verify

Tests to be implemented for the mail stack

• [ ] humanity verification mail (sent to unknown sender)
• [ ] send a mail to an external address adds it to the authorized senders list
• [ ] report (sent to agentj users)
• [ ] block/allow policies (quarantine mail or not)
• [ ] sender/domain manually added to authorized/blocked senders
• [ ] incoming virus/spam are blocked, except for allowed senders
• [ ] outgoing virus/spam are blocked, and alerts are created
• [ ] quota
• [ ] if enabled, alerts mail should be sent on outgoing virus/spam/quota exceeded
• [ ] non delivery message
• [ ] sender verification (no open relay, separation of different domains)

For each mail, should be verified

• [ ] sender and recipient are correct
• [ ] for mail sent from or via agentj, dkim signature is present and valid
• [ ] smtp return code:
  • [ ] for incoming mail: dropped silently for virus/spam, refused for unknown recipient
  • [ ] for outgoing mail: dropped silently for quota exceeded