[CentOS] Mail[x] / Sendmail - CentOS 3

I'm upgrading some servers from rh7.3 -> CentOS 3 and
have several scripts that use "mail" to relay
messages to my mail server.

Am I correct on the assumption that you now have
to have sendmail running to use mail, where
as previously you did not? Or am I missing something?

It's been driving me crazy for couple days trying
to figure out why "mail" works on 7.3 without sendmail
running and will only work with sendmail running on CentOS 3.

I'm guessing as part of a "secure install" you now need to
use "client queue ruuner" part of sendmail?

Sure liked the old way, anyway to revert?

Just don't like to run an additional process for just a couple of emails
a day, or I guess I could use a cron job to process emails.