IMAP4 backend service not authenticating to any mailbox on that server.
NO AUTHENTICATE failed."";Msg=""AuthFailed:LogonDenied
EventID 1102: The IMAP4 service failed to connect using SSL or TLS encryption. No valid certificate is configured to respond to SSL/TLS connections. Check the configured host name as well as which certificates are installed in the Personal Certificates store of the computer.
1. Remove the certificate and re-add the certificate again on that Exhange 2013 server.
2. In Exchange Management Shell run the following: Enable-ExchangeCertificate -Thumbprint XXXXXXXXXX -Services POP,IMAP
3. Restart the Imap and Pop frontend and backend services.