Hi, it looks like, when the "Reject sender and login mismatch" option is checked in ISPConfig, Postfix rejects the Sender address (error message: "Sender address rejected: not owned by user") if the mail sender belongs to the "Domain alias". Example: Main Mail Domain: example.com Alias Domain: example.it Sending e-mail with smtp account "[email protected]" and mail header "From: [email protected]" In my /etc/postfix/main.cf file I see: Code: smtpd_sender_restrictions = reject_authenticated_sender_login_mismatch, permit_mynetworks, check_sender_access proxy:mysql:/etc/postfix/mysql-virtual_sender.cf, reject_sender_login_mismatch, permit_sasl_authenticated, reject_non_fqdn_sender, reject_unlisted_sender so it looks like the reject_authenticated_sender_login_mismatch check is performed before any other check. Is it an ispconfig fault or is it some misconfiguration on my side? Thanks in advance.
Postfix can not resolve alias domains for this as far as I know as they are basically wildcards. You can try to remove the alias domain and create the addresses that shall be aliased as alias email addresses instead.
