To send mail from a Perl program, you have at least four choices:

1. Use a MUA (mail user agent). e.g. mail, mailx
2. Use a MTA (mail transport agent), e.g. sendmail
3. Connect to a SMTP server
4. Use a CPAN module

I personally use the Mail::Mailer CPAN module, which hides these choices behind a simple interface. The recent Perl Email Project, see Email::Simple, started by Simon Cozens and now maintained by Casey West, is worth a look, though I haven't used it.