I agree with siberian! His constant insistance of this caused me to make the switch and, after a couple of fits and starts, I would much rather use NET::SMTP than sendmail. It really is easier to maintain and is far more robust than sendmail. Even my web host agreed that it was a better choice as far as they were concerned. At the very least, give it a try... you won't be sorry!
There's always a better way. The fun is trying to find it!