Hi Wietse, that's right, it isn't listed. But it was a non exisiting subdomain the spamer sent the mail to. The mail address was like zirkel.in...@nonexistingsub.domain.net So the mail was directly delivered to the A record (which is wildcarded). What i don't get is, why did postfix forwarded the message to the other host without permission? Is this linked to the issue you mentioned?
----- Original Message ---- The machine is MX host for REMOVED, but you broke Postfix by not listing that domain in virtual_alias_domains, mydestination, relay_domains, or virtual_mailbox_domains. Wietse