Updating my msn messenger
When Microsoft will discontinue Delta Sync protocol, Windows Live Mail program will stop synchronizing emails for all Outlook and other Microsoft accounts.
That's why Microsoft sent the email to all users informing about this upcoming change.
Although that was a nice initiative by Microsoft to inform the users in advance about the change but it has started giving problems to many Windows Live Mail users.
Actually Microsoft has been upgrading all Outlook and other Microsoft email accounts to a new service called Outlook Mail (Preview) since May 2015.
First of all if you have not installed the KB3093594 update yet and your email account is working fine in Windows Live Mail 2012, DO NOT install the update at the moment. Microsoft has already updated and re-released the update twice.
First the previous version of this update (released on December 11th) caused crashing problems in Windows Live Mail program when the user tried to update the Calendar.
Then Microsoft released a new version of this update on December 17th which started this syncing problem.
Microsoft has already acknowledged the issue and they are investigating it.