One of our users suddenly began experiencing a severe draining on his iPhone battery. There are variety responses to this topic, the least of which was to change the iPhones mail retrevial from Push to Fetch. Howver, other iPhone users were not experienceing this issue. So we set out to troubleshoot what was happening. After two days of research, below is our results and the resolutin that worked for us.
Constant polling in Push mode
The first thing we detirmined was that the phone was constantly polling the exchange OMA (Outlook Mobile Access) website of the exchange server. This was both visible and audible if you are near a set of computer spearker that can pick up the iPhones RF. Switching the ActiveSync mode to Fetch, did indeed resolve the battery issue, but it simply masks the problem. If you are an Exchange Administrator or have a good relationship with one, you can verify this is an issue by checking the Excahnge OMA website logs in iis. These are difficult to read, but for a medium sized business, you’ll see a noticable increase in the traffic to that website, as the iPhone polls iis constantly. This might also be noticalbe in Firewall https logs.
Resolution
We found the problem to be caused by a corrupt “Meeting Request” in the users mailbox. The phone was not able to open this and process automatically, thus causing an error and the ActiveSync polling to restart. No other functionality seemed to be impared, only that ActiveSync push would constantly fire, due to an inability to sync all mail items.
1) To eliminate it, we sorted the Users Inbox by Type in outlook.
2) We then deleted all the meeting or calendar mail requests.
3) Empty the deleted items as well to completely remove the corrupt invititation.
4) Deleted the iPhones Exchange Account, recreated it, and let the mail sync up.
Once you delete the account, you can recreate it using the AT&T infomration below. No data will be lost, as this is simply a syncronized copy of the exchange server.
AT&T Support On-Line