Update: Looks like YouMail has gotten to the bottom of the issue. Turns out that it was a bug in the code (a bug they were aware of, no less) and they didn't realize how severe the issue actually was. They've since corrected the issue (or are in the process of), and will be back in the Android Market shortly. For full details, check out the YouMail Blog.

YouMail, a popular (and free) visual voice mail solution, mysteriously disappeared from the Android Market today. In an email notification, the makers of YouMail were informed that the app was pulled due to a complaint from T-Mobile that the app was causing "adverse network disruption." Here's the full text of the email:

This is a notification that the application, YouMail Visual Voicemail Pro, with package ID com.youmail.android.wm has been removed from Android Market due to a violation of Android Market developer terms. It has come to our attention that this application could be used in a way that is harmful to devices, networks, or users. Specifically, we have received a complaint from T-Mobile that this application is causing adverse network disruption. We encourage you to contact T-Mobile to negotiate a revision and/or agreement to republish this application and update your existing users.

Sounds a bit fishy, no? To start with, YouMail has been around for a while now, serving over 75 million unique users, and raising almost $13 million to further build their technology. It seems odd that T-Mobile would complain only after YouMail has already handled over a billion calls, while all other carriers remain silent (even those who preload YouMail on their devices, like Viaero or Immix). It's also worth noting that T-Mobile never contacted YouMail directly before lodging the complaint.

YouMail's blog post on the subject speculates that this action could be anti-competitive behavior (because YouMail is free, and, according to their blog, far superior to T-Mobile's service), but the truth isn't exactly clear. If and when more details emerge, we'll be here to report. In the meantime, YouMail is still available from Amazon's App Store.

Source: YouMail Blog