SMTP 553 5.7.1: sender address rejected – fix

daniele@mikweb: ~/errors — less smtp-553-5-7-1-sender-address-rejected.md

What the message looks like

553 5.7.1 <info@example.com>: Sender address rejected: not owned by user anna@example.com

reject_sender_login_mismatch is active and the sender address is missing from smtpd_sender_login_maps.
Sending from a shared address (info@, noreply@) with a personal login.
The application sets a different envelope sender than the login address.
The map only lists the address itself, not aliases or capitalised variants.

Show sender restrictions and login map
postconf smtpd_sender_restrictions smtpd_sender_login_maps
Check which login owns the sender address
postmap -q info@example.com $(postconf -h smtpd_sender_login_maps)
Show the submission port settings
postconf -M submission/inet
Find rejected senders in the log
journalctl -u postfix --since '1 hour ago' | grep 'Sender address rejected'

For shared addresses add an entry to the login map, e.g. info@example.com anna@example.com,ben@example.com.
For hash maps run postmap, then postfix reload.
In applications set MAIL FROM to the login address and use the desired address only as Reply-To.
Do not just disable the check: without it any logged-in user can send as anyone.

553 5.7.1 is about the sender address when you send. 550 5.7.1 is usually a recipient-side policy or relay access denied.

Yes. The login map accepts several logins separated by commas. With SQL maps the query returns several rows.

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