Another alternative that might work well for you, if you're simply trying to send mail from your script, is the Mail::Mailer module, which is quite simple to use and will autodetect your MTA (Message Transfer Agent) automagically.
in reply to SMTP and Authentication
It's pretty slick and has worked very well for me; some of my scripts periodically poll different services on my OpenBSD boxes and kick out a report to me (using Mail::Mailer) if there is something I should know about.
Interestingly, if Mail::Mailer can't detect Sendmail, mail, Mail, or mailx on your system, it will use the aforementioned Net::SMTP module to deliver your message. ;-)