Exchange 2013 can produce IMAP issues when trying to authenticate. This is a known bug in CU9 and CU10 but in my CU12 scenario also happens.

The IMAPSettings EnableGSSAPIAndNTLMAuth atribute must be set to False in order to solve the problem.

Symptoms

Yesterday, when one of my users asked me how to configure the email client using IMAP I realized … Read more