This post serves more as a personal reminder to me than anything else. I ran into a situation at work where I couldn't figure out why sendmail on a Solaris 10 system wasn't using the 'smart host' that I could clearly see was in /etc/mail/sendmail.cf. Long story short, by default, sendmail on Solaris 10 uses /etc/mail/local.cf. You have to tell it you really want to use sendmail.cf. It serves a purpose though because a default install won't have the mailer daemon hanging out there for the rest of the world to probe (even if it won't be an open relay).

To make your intention known that you want to use sendmail.cf, you must edit the smtp:sendmail service properties. You can easily do that with svccfg. Like so:

svccfg -s smtp:sendmail setprop config/local_only=false

Then you have to refresh the instance to reload the xml files for the service...

svcadm refresh smtp:sendmail

And then all is well. The service should be restarted and using sendmail.cf!