Apple has begun converting the email addresses of MobileMe users, located at the me.com domain, over to iCloud.com adresses, reports Macrumors. The changes will begin with users of iOS 6 beta 3, which was released earlier today to developers.

If these developers use a me.com email address with the beta, they will be converted over to an @iCloud.com address that matches the previous @me.com address. New users of iCloud who sign up for the service will get a fresh new @iCloud.com address to go with their syncing services. Presumably, this behavior would cross over to regular users once the OS is released this fall.

This would solve some issues that we’ve been seeing on Mountain Lion and iOS, where a non-Apple email address that is also used as an iCloud contact could not be used as an iCloud mail account. If a user of a Gmail account, for instance, signs up for iCloud using their Apple ID, and then adds their Gmail account to Mountain Lion, they end up receiving errors when trying to activate iCloud mail. Now, they’ll have a dedicated iCloud email address to use with the service.

Apple discontinued MobileMe on June 30th, but is offering transition services for a while yet. The @me.com email addresses were themselves a transition from the earlier @mac.com domains attached to Apple’s .Mac services.