Here is some output of strace
execve("/usr/libexec/dovecot/deliver", ["/usr/libexec/dovecot/deliver", "-a", "komodo@somedomain", "-f", "someuser@somedomain"], [/* 22 vars */]) = 0
So it's clear that deliver have those variables, but then i can see this
execve("/usr/sbin/sendmail", ["/usr/sbin/sendmail", "-i", "-f", "<>", "--", "someuser@somedomain"], [/* 2 vars */]
And there is empty -f , so here is the problem.
I am not convinced that this is the problem. This looks like a valid rejection or vacation notification mail being sent out, probably from Sieve; notice that the original sender is specified as recipient and that the new sender is empty, indicating an automated message. So, what caused this message to be sent out? It is definitely not a redirect.
Thanks for the answer, but this must be the problem, because when i run sendmail from command line (exactly like in the strace output)
[root@OVZ.mail ~]# /usr/sbin/sendmail -i -f <> -- komodo@domain.com
511 Headers specify no receipients.
sendmail: Unable to submit message.
[root@OVZ.mail ~]# echo $?
67
And there is exactly return code 67 as reported by LDA
Regards
Martin