Apple recently released the iPhone4 and an update to the iPhone operating system (iOS4), which is available for download for older iPhone devices. Devices running iOS4 require a configuration patch to continue using ActiveSync with Exchange Online.
Steps Organization with iOS4 Devices Must TakeOrganizations with devices running iOS4, must install an updated configuration profile from Apple on their device. Information about obtaining and installing the profile can be found in the Apple support knowledgebase, Article TS3398.
Failure to install this patch may result in a degraded performance for iOS4 devices, including the inability to connect to Exchange Online via ActiveSync to synchronize message and calendar items.
The Microsoft Online Services team is committed to providing the highest quality service experience to our customers. Organizations that have questions should not hesitate to contact Microsoft Online Services Technical Support.
We will update this blog post as additional information is available.
this sound exactly identical to the issue with 10.6.3/10.6.4 and Mail.app. MS Online just resolves those tickets as "mail.app is unsupported, please use buy entourage" which is a great cop out.
Find a step-by-step info in german to apply the iPhone patch:
Sorry this 'fix' from Apple is not working and it has not corrected the problem.
It did kind of work for a little while but we are constantly getting the 'connection to the server failed' message almost all the time. The iPhone is also not staying synched with Exchange. I am using BPOS. If I read emails on the iPhone 3Gs running OS4, when I go to Outlook 2010 on my PC or OWA the emails show as unread. Also the emails are not all being 'pushed' to the iPhone in realtime.
See this thread on TechNet -
I applied the patch, rebooted my device (several times) and still got the error. I deleted my exchange account and recreated and was able to connect fine since. I'm using BPOS.