We have iPhones connected to the Exchange 2007 server. Everything is working. In fact, Outlook, OWA, Outlook Anywhere, and Autodiscover are all working very well. But e-mail sent to the Exchange accounts arrives in Outlook pretty much instantly, and seems to take 15 to 20 minutes to reach iPhone, most of the time. I have looked for some optimization articles, and I mean to say optimization, as it never fails to arrive. I can't really find much on iPhone, specifically. But this does not seem like the AUTD experience. Maybe there is something I don't have tweaked right, and I could use some experienced suggestions for optimization in this area.
It's Exchange 2007 SP2, with all the rollups, on Windows 2008 SP2, all updates.
Exchange is behind a SonicWall TZ 210.
iPhones are 3GS with probably not all the latest firmware but close... like, v.3.1x.