One of the most common questions I’ve been hearing after I published my articles on how to set up Exchange ActiveSync with the iPhone 2.0 software is whether or not you need an enterprise data plan from AT&T in order to use it. There were conflicting rumors going around prior to the launch, and AT&T and Apple haven’t been clear on the subject.
Here’s the answer: You do not need to buy the $45 Enterprise Data plan from AT&T for Exchange ActiveSync and corporate VPN access to function with an iPhone 3G or upgraded original iPhone.
This may not be the whole story, though. Although the Exchange and VPN features exist and are functional with either the $20 EDGE or $30 3G data plans from AT&T, the company may require you to buy the $45 Enterprise Data plan. I am not a lawyer, but the terms and conditions are no help.
And the wording on the iPhone web site and iPhone business site aren’t clear, either: They say you must get the Enterprise Data Plan “to access corporate email, company intranet sites, and/or other business solutions/applications”. Although this would certainly include business Exchange users, it would also include non-Exchange users accessing business sites, as well as business users accessing their Exchange server with IMAP. And it would seem to exclude those using Exchange for personal email (which is quite possible).
Note that, although these enterprise features are fully functional in EDGE iPhones with 2.0, there is no Enterprise Data plan for them! So if you have an original iPhone you have to use the $20 data plan no matter what!
Finally, although I can’t tell you whether AT&T allows it explicitly, many people have been successfully using their iPhones to access Exchange ActiveSync with both the $20 and $30 data plans with no problems at all.