It’s a bit of smartphone whodunit as the finger-pointing continues to name suspects in the hunt for the WP7 data hog. After user complaints that their Windows Phone 7 devices were consuming much more data than usage would account for, Microsoft looked into the situation and confirmed their suspicions: there is indeed a “third-party solution commonly accessed from Windows Phones” that is eating up all your 3G data allotment. While Microsoft has yet to name the guilty party, the latest evidence to come our way names miscommunications with Yahoo Mail servers as the culprit.
Microsoft enthusiast Rafael Rivera had a feeling that Yahoo Mail may have been to blame for the troubles, but tracking down where the problem was, if it even was there, proved pretty tricky. Since the phones try to communicate with Yahoo’s servers over an encrypted connection, Rivera wasn’t easily able to see what was going on. After forcing a clear-text IMAP connection, and looking through his transfer logs, he spotted far more data than he was expecting.
It turns out that the Yahoo Mail servers, in a response to a query for basic information on recent messages, send back something like twenty-five times the amount of data you’d expect, including the full text of messages. Repeat this over and over, and you have what could account for the mysterious WP7 runaway data.
This could be just part of the problem, perhaps with other phone settings exacerbating the condition, but it looks like a promising idea. We’ll have to wait for Microsoft to follow up with WP7 users to confirm.
Update: Head of nail, meet hammer; Microsoft confirms it.