I'm having an issue with Gmail for your domain and the iPhone.
My iPhone will not download any new email from my Gmail for your domain hosted account. My regular gmail pulls everything, the Gmail for your domain downloaded one received 5/29/07 and then 10/4/06 and older.
I have it setup as an other account since if you set it up as GMail it puts the @gmail.com on your user account; which doesn't work for Gmail for your domain.
Mail.app is working perfectly and downloading all mail.
Last night I reset GMail to enable POP3 and mail.app and iPhone are currently downloading every message again, it's on September 2006 so far.
Hopefully they'll both download all messages up until today.
Anyone using GMail for your domain and iPhone?