I finally got around to take another look, sorry for the delay. The problem is the "noplaintext" in smtpd_sasl_security_options Here's a small config diff that fixes the problem:
# diff -Naur main.cf.bug main.cf --- main.cf.bug 2021-09-15 19:14:02.919982259 +0000 +++ main.cf 2021-09-15 19:18:04.765338947 +0000 @@ -48,8 +48,7 @@ smtpd_sasl_type = dovecot smtpd_sasl_path = private/auth smtpd_sasl_local_domain = -smtpd_sasl_security_options = noanonymous,noplaintext -smtpd_sasl_tls_security_options = noanonymous +smtpd_tls_auth_only = yes broken_sasl_auth_clients = yes smtpd_sasl_auth_enable = yes smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination I believe this confirms the problem to be a local config one so I'll mark the bug as invalid. Let me know if the above diff doesn't make it work for you. ** Changed in: postfix (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1940603 Title: postfix/smtpd: fatal: no SASL authentication To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/postfix/+bug/1940603/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs