#！/usr/bin/perl -wuse strict;use Net::SMTP;my $to = 'toMail';my $from = 'fromMail';my $site = 'mail.126.com';my $smtp_host = 'smtp.126.com';my $pop_host = 'pop3.126.com';my $username = "userName";my $password = "password";    &writeAMesg;sub writeAMesg{    my $smtp = Net::SMTP->new( $smtp_host, Timeout=>60, Debug=>1 );    $smtp->auth($username, $password);    $smtp->mail( $from );    $smtp->to( $to );    $smtp->data();    $smtp->datasend("To: $to\n");    $smtp->datasend("Subject: A message from server\n");    $smtp->datasend("\n");    $smtp->datasend("This is just to let you know\n");    $smtp->datasend("The flight is coming, Please check it out on time.\n");    $smtp->datasend("\n");    $smtp->dataend();    $smtp->quit;}