In the search you will find several version of the SMTP setup, some work some don't. Your default mail should work but sometimes it takes many hours for the mail to be sent from their email queue.
Since you are getting no errors in your ACP error log I suggest this search http://www.phpbb.com/community/search.p ... &fid[0]=46
Godaddy is a great registrar, but suck at webhosting.
Most users have email issues with Godaddy.