I am testing the handling of mail bouncing. When I send a test email to a bad domain, for example: firstname.lastname@example.org, I get the following error in my log:
SYSERR(root): blahblahfail.org.mydomain.org. config error: mail loops back to me (MX problem?)
It seems that if dns fails on the destination domain, sendmail will append my domain to the bad domain.
Why does this happen? And should I expect mail to bounce if the domain is bad? The Unknown-user @ good-domains type of bounces do work for me.
Possible relevant sendmail config lines:
Notes: I have tried removing the always_add_domain Feature. I have my domains listed in /etc/mail/local_host/names