Microsoft promised to get to the bottom of the issue that saw large numbers of Windows Phone 7 users reporting mysterious chunks of data going missing – and it has.
When the issue first came to light a month or so ago Microsoft pleaded innocence despite the frustrations of subscribers seeing their precious mobile data allowances getting frittered away without their knowledge, or consent. And credit where credit's due – turns out it was right. It wasn't Microsoft's fault at all. It was Yahoo's.
“We have determined that an inefficiency exists in the synchronisation of email between the Windows Phone mail client and Yahoo Mail,” Microsoft said in a statement. “This inefficiency can result in larger than expected data usage for a very small percentage of users.”
So, the more argumentative among you may be thinking, Microsoft isn't entirely blameless, as synchronisation takes two to tango and WinPho 7's own mail client is one of the duo taking up the beat.
Fair enough, and it should be noted that Redmond only appeared to cotton on to what was happening when Microsoft blogger Rafael Rivera analysed the IMAP data packets leaving Windows Phone 7 and found Yahoo's servers to be behaving differently to other mail services'.
And how would that be visible to the end user? “Your phone is downloading 25 times as much data as it normally would, had you sided with another e-mail provider.” Ouch.
Microsoft has promised it is working on a fix with Yahoo. In the meantime it advises users signed up to Yahoo on Windows Phone 7 devices to configure their mail service to only download new content when asked to, rather than automatically.