Finally figured this out. Pine works fine with .mac
Set the following in your Config:
user-domain=mac.com
smtp-server=smtp.mac.com/user=username/notls
inbox-path={mail.mac.com/ssl/novalidate-cert/user=username}inbox
To get sending to work, scroll way down and add:
customized-hdrs=From: "Your Name" <username@mac.com>
Without a matching FROM header and user-name, smtp.mac.com will not authenticate.