I have used Net::SMTP:SSL together with Mime::Lite against yahoo in the past.
Example (untested)
#!/usr/local/bin/perl -w
use Net::SMTP::SSL;
$smtp = Net::SMTP::SSL->new('mailhost');
$smtp = Net::SMTP->new('smtp.bizmail.yahoo.com', Port=>465);
$smtp->auth($user, $password);
$smtp->mail();
$smtp->to('xxx');
$smtp->data();
$smtp->datasend("To: xxx\n");
$smtp->datasend("\n");
$smtp->datasend("$mime->as_string");
$smtp->dataend();
$smtp->quit;
You need to use the Winnipeg PPM to get any SSL related libs on Windows.