I'm running a mail server with sendmail 8.9.3 on a linux box. It takes
place on a DMZ behind a firewall.
My domain is mydomain.com
When i've got an header error or a recipient error, my firewall try to
send a message to the users using the mail server.
When this message is received by the mail server, i've got this error
log lines :
Apr 1 07:55:05 mail sendmail: HAA15376: ruleset=check_mail,
Apr 1 07:55:05 mail sendmail: HAA15376:
nrcpts=0, proto=SMTP, relay=fw.mydomain.com [mail IP address]
and the user isn't informed !
mydomain.com is correctly defined.
firewall.mydomain.com domain is not defined in my domain.
How my mail server can accept this message header ?