Ok so I have spamassasin setup here and it does a great job of identifying spam. But it inserts a spam header (X-Spam-Flag:) in the message instead of just deleteing it. So how do I just have those messages deleted. Tag it and Bag it
Squirrelmail is just a webmail frontend for your mailserver and has no possibility to automatically move messages based on headers added by SpamAssassin. You should look in the SpamAssassin manual. You could send all messages that are almost 100% certain spam to the mailbox /dev/null or a mailbox that is periodically cleaned by a cron job.