Everyone seems to have their preference for a mail module. I use Mail::Sendmail. It's platform independent, yehaw.

Sample code (previously posted here, and here):

use Mail::Sendmail;

# Create the message hash
my %mail = (
    To => 'You <your@address.com>',    # To address..
    From => 'Me <my@address.com>',    # From address..
    Message => 'Hello, world!',    # The message body..
    Smtp => 'your.mail.server'    # erase this if you want to use "loc
+alhost" (default)
);

# Send the message
unless (sendmail(%mail)) {
    # Error!
}

# All is well.
[download]

Update:
Whoops, i forgot to add that, the Mail::Sendmail FAQ talks about sending HTML email.