Microsoft blames Windows Phone 7 About Data usage issue on unnamed 3rd party

Microsoft has issued a vague response to say that the company has determined the cause of excessive Windows Phone 7 data use issues. The main culprit fingered by the Windows Phone 7 community over this issue (though not named in the statement) is Yahoo! Mail. Windows Phone 7 has special support for Yahoo! Mail allowing it to treat Yahoo! accounts as something more than regular POP or IMAP mailboxes (similar special support also exists for GMail and Hotmail accounts). The other part of the data usage problem is that the data usage is occurring primarily over 3G—which for most users, subject to restrictive network contracts, is a scarce resource—rather than WiFi. Microsoft says that the issues affect only a few percent of Windows Phone 7 customers. The culprit behind some mysteriously high cellular data usage by Windows Phone 7 devices has been attributed to a third-party service, and not necessarily the software OS itself, Microsoft said today.

The company also said that it was at work on ways to fix the problem, which had affected only a "small" percentage of Windows Phone customers:

We are in contact with the third party to assist them in making the necessary fixes, and are also pursuing potential workarounds to address the configuration issue in case those are needed. A small (low single-digit) percentage of Windows Phone customers have reported being affected.