Feb 1, 2011 12:41 GMT  ·  By

Recently, Windows Phone 7 devices have been reported to consume far more data then they were supposed to, and it seems that Microsoft has already confirmed the “third-party application” responsible for this, namely Yahoo! Mail. But this was not the only reason for which Windows Phone 7 devices were sending a lot of data when they were not supposed to, it seems, as Microsoft also confirmed an issue with the Exchange ActiveSync (EAS) email synchronization protocol.

We should first note that the problem with Yahoo! Mail was already demonstrated by Rafael Rivera, who published his findings in a post on Within Windows.

A few hours after his post, Microsoft confirmed the issue too, it seem. Here's what the software giant announced, according to a recent article on WindowsPhoneSecrets:

We have determined that an inefficiency exists in the synchronization of email between the Windows Phone Mail client and Yahoo! Mail.

This inefficiency can result in larger than expected data usage for a very small percentage of users.

Microsoft and Yahoo! have worked together to identify a fix, which will be rolled out in the coming weeks.

Most probably, the fix would be included in the upcoming Windows Phone 7 software update, which is bound to arrive on handsets in a few weeks.

In the meantime, however, users who have experienced the problem are offered a temporary solution, so that they don't see their data allowance eaten away.

They should head to “Settings,” then “email & accounts,” choose “Yahoo! Mail.” Here, they need to click on the setting under “Download new content,” then: “select a less frequent setting. If you are using the default setting (every 2 hours), change this setting to ‘manually’.”

After that, they would have to go to “Download email from,” and “select a shorter time range. If you are using the default setting (the last 2 weeks), change this setting to ‘the last 7 days’.”

As stated above, the issue that caused the aforementioned data leak in Windows Phone 7 is not limited only to Yahoo! Mail, and Microsoft confirmed that some problems with Exchange ActiveSync also exist, although only a small number of users would be affected by it:

- This issue can be caused by email that exceeds the mail server email size setting or is sent to an invalid email address - This issue can potentially affect email services that utilize the EAS protocol – Outlook and Gmail for example - The immediate mitigation is for users to delete mail that appears “stuck” in the outbox - This is currently scheduled to be fixed in a near-term end user update from Microsoft.

What remains to be seen is when this software update might become available for Windows Phone 7 devices out there. The update was announced in early January, and was said to be on its way to users in the next few months.