When you notify user to install that KB, make sure you tell them to refresh their server setup w/ the latest IMAP/SMTP settings as well. Many are still using the old SYNC mechanism unaware of their settings are outdated and no longer work w/ this KB.
This is my problem: I installed the KB and it stopped sending and receiving from Hotmail; tried the community, then got a response from the Microsoft Community saying that the KB was re-updated, and to install that; once done, it still will not receive or let me see any emails in it's Inbox.
I think that you are on the right track and I need to refresh the server setup with the latest settings, BUT... HOW DO I DO THIS??