No matter what i tried i could not get the iPhone to sync with exchange, pop, or Imap. I punched holes in the firewall, white listed at&t 's ip address block to no avail. Palm phones, Microsoft mobile phones all work but no luck with the iPhone.
Heres what i did...
I created the user a gmail account.
Went into active directory and created a new OU call mail forwarders
In the container I made a new contact
http://www.msexchange.org/tutorials/MF015.html
Created the contact (named it user mail forwarder) with an SMTP address of the newly created gmail Account
Edited the users exchange account (exchange general tab) went to delivery options
chose forward mail to: found my newly created contact
checked the box to deliver to forwarding address and mail box
Entered the gmail account information in the iPhone
Logged into the gmail account and edited the mail settings and set the reply to address to correspond with the users work email
Done deal