Now that the iPhone 4 and iOS4 have been released most of the complaints are centered around the antenna attenuation issue. Earlier this week complaints about the iPhone not syncing properly when configured to use the Activesync protocol to connect to a Microsoft Exchange Server resulted in Apple released a fix for the problem. The cause basically turned out to be a timeout in the Exchange Active Sync (EAS) task on the device. The default on the device was 30 seconds but has now been increased to 240 seconds. The symptoms are that the device wouldn't sync the mailbox (typically calendar) and it usually happens upon initial sync of the device with the mailbox.
What isn't getting as much buzz is a problem where the device doesn't appear to send email when Exchange2010 is published by a protocol inspecting reverse proxy server like Microsoft ISA, TMG, UAG, Juniper SA, etc. The issue doesn't appear to happen when the device is internally connected to the LAN (via WiFi) and therefore bypasses the Edge proxy/firewall.
I've conducted some tests our labs and have found the following results:
- Microsoft ISA Server 2006 – Send/Receive/Sync folders – no issue.
- Microsoft TMG Server – Send/Receive/Sync folders – no issue.
- Microsoft UAG Server – Receive/Sync folders but the device can't send.
So what's the conclusion? Well it would appear that UAG, which is based on TMG's firewall, is filtering the packet, however nothing appears as dropped in the firewall or web proxy logs. A current working theory is that the EAS task that the iPhone uses to send mail has a similar short default timeout like the folder sync task. Applying the profile update supplied by Apple may not be increasing the send task. But again, that's just a theory…
I'll post more information here as gather it or you can add to the conversation threads here:
Microsoft Technet Forums
UPDATE #1 – July 1, 2010
I had to share this – it's just too funny.
UPDATE #2 – July 1, 2010
See the Microsoft Exchange Product Group's post regarding the status of the issues here:
UPDATE #2 – July 2, 2010
Yesterday folks from Microsoft PSS Exchange and IAG/UAG support and Apple engineers conducted traces from the iPhone through UAG and then onto Exchange it was confirmed by Apple developers/engineers that this is another bug in the device.
UPDATE #3 – September 9, 2010
Almost three months after the original iOS 4.0 was released, Apple released iOS 4.1 I've confirmed that this does correct the issues with UAG server as well as a number of other issues originally replorted. Although this seems to be a long time to correct the issue, I hope Apple has conducted extensive testing with this release. My personal experience is that iIOS 4.1 is faster than 4.0.x Enjoy!