#!/usr/bin/perl
#
#
use strict;
use Net::SMTP;

my $DEBUG = 1;

my $smtp;
$smtp = Net::SMTP->new('mymailserver.net', Hello => "myotherserver.net", Debug => 1,);
die "Couldn't connect to server" unless $smtp;
print "Server connection opened\n";

$smtp->auth('myuser', 'test123');

...