[colug-432] sendmail using wrong domain

[Scott Merrill]

Aloha.

I have a Red Hat Enterprise Linux v5 system running as a virtual
machine inside an ESX 4 cluster. The system is resolvable at both
host.osu.edu and host.dept.ohio-state.edu. /etc/hosts defines
host.osu.edu as the public IP address, and there is no specific entry
for host.dept.ohio-state.edu.

`hostname` returns host.osu.edu, and `dnsdomainname` returns osu.edu.

When I send mail manually (`mail -s skippy at skippy.net test`), the
message is sent from user at host.dept.ohio-state.edu.

cron mails are failing to be delivered, because Sendmail is trying to
send mail to root at host.dept.ohio-state.edu, but sendmail is not
listening on that interface: it's only listening on localhost.

I tried adding host.dept.ohio-state.edu to /etc/hosts as 127.0.0.1,
but that didn't seem to work.

Do I _have_ to edit /etc/mail/sendmail.mc to define a masquerade
entry? Or is there another way for me to tell this system that is
host.osu.edu, and should only ever use that address for sending mail?
I want all mail to be sent from -- and delivered too --
root at host.osu.edu. This machine only needs to send mail from cronjobs,
and will not be a publicly accessible mail server.

Thanks,
Scott