I have the following setup
mailserver.domain 10.0.0.3 - centos 5.6, qmail works fine
webserver.domain 10.0.0.4 -centos 5.6, sendmail configured with smarthost = mailserver, when sending mail to an outside domain (like yahoo.com) it works, but when I send mail to user@domain it doesn't.
the maillog on webserver says that the mail was sent to firstname.lastname@example.org the maillog on mailserver says it can't send it for some reason - I can't edit anything on mailserver yet, and I was wondering if I could convince webserv not change the address to ip .
I also have a windows box on the network, that successfully sends mails via mailserver to anyhost including domain.
Edit: I've installed postfix instead of sendmail and now it works.
Thank you for your interest.