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Understanding the Windows Phone Data Bug

written by: •edited by: Simon Hill•updated: 2/18/2011

The Windows Phone 7 data bug has been traced and attributed to problems with the way Yahoo Mail handles e-mails - and it seems that the same problem affects iPhone too...

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    What's Wrong with Yahoo Mail on Windows Phone 7?

    Windows Phone data bug explained - it's all down to email! Since the launch of Windows Phone 7, some users in the USA have complained of problems with their data usage, with high phone bills indicating that some form of “data leak” has been in operation.

    Initially ignoring the concerns, the problem has become big enough for Microsoft to investigate and find its cause with a view to resolving the underlying issue. Admitting to looking at a few apps that might be the cause of the leak, it has since transpired that the problem is with Windows Phone’s connection to Yahoo Mail. Yahoo admitted their part in the error, while also underlining the fact that only the Windows Phone platform is affected.

    To muddy the waters further it now seems that the same problem exists on iPhones. So just what is going on with the Windows Phone data bug, and when will it be resolved?

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    How the Bug Occurs

    The Windows Phone data bug is related to the use of Yahoo e-mail accounts and IMAP servers. Thanks to a couple of different interpretations of the loosely defined IMAP standards, Windows Phone 7 users experience increased data use; when requesting a single e-mail message to be downloaded from the Yahoo IMAP server, a whole bunch of additional data is sent, often relating to other e-mail messages.

    What is most interesting about the problem is that following the initial analysis by experts (which after some discussion basically saw an agreement that both Microsoft and Yahoo should be improving the way they request and respond to the IMAP requests) it has since transpired that the problem is not limited to Microsoft’s Windows Phone 7 devices, as claimed by Yahoo.

    As revealed at the issue also affects iOS devices such as the iPhone.

    So why hasn’t this problem been spotted before? Well, it could be due to the fact that a Yahoo account on an iPhone requests only 50 messages at a time, as opposed to Windows Phone 7’s 200.

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    Resolving the Windows Phone Data Bug

    As things stand there is no way to avoid unnecessarily high data use when using a Yahoo Mail IMAP account on a Windows Phone 7 device. It should be noted, however, that the problem does not affect Exchange e-mail or POP e-mail accounts, or indeed IMAP accounts with other e-mail providers.

    So one obvious workaround is to avoid using Yahoo Mail on your Windows Phone until the issue is resolved; however, this might be difficult for anyone using a Yahoo IMAP e-mail account.

    As both Microsoft and Yahoo are said to be currently working together towards a resolution for this issue, the best way to work around the problem short-term would be to disconnect your Yahoo IMAP account from your Windows Phone 7 device and use e-mail forwarding in your Yahoo account to send your messages to another account temporarily until the problem is resolved.

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    Within Windows,

    Images: Screenshot by author