my $sender = 'yourname@example.com';
my $msg = MIME::Lite->new(
        Type       => 'TEXT',
        From       => $sender, 
        To         => 'theirname@example.com',
        Subject    => 'Simple Greeting'
        ReplyTo    => $sender,
        ErrorsTo   => $sender,
        Data       => 'Greetings, Lifeform!'
     );

$msg->send_by_smtp( 'localhost' )
   or die "Unable to send message; reason $!\n";