I have a customer with SBS 2003, SP2 and Exchange Server 2003, SP2 and one iPhone 3G user. IMAP is enabled, ports are pinholed through the firewall and router. The customer is using a GoDaddy certificate. I have verified all the IMAP settings I can find in Exchange MMC against a working server system that iPhones work with. I have not been through the IIS settings to compare them as yet, but have reviewed them against all the information I can find for correctness. I can access the user's e-mail through the internet and internally using Outlook Express with IMAP just fine. The iPhone attempts to connect, lists the e-mail folders for the user, but never downloads any mail. I have tested the iPhone on another server that works with other iPhones with a different user and it worked fine. So - iPhone is verified, Outlook Express/IMAP works, any ideas on what to check next? After reading at least a hundred articles, I haven't come up with a solution.