Mail fetching and Exchange 2016

Our mail server was recently upgraded to Exchange 2016. Since the upgrade of Exchange, we have not been able to fetch email. The following error is shown when settings are saved: FAILURE :E-mail settings saved successfully. But error occurred while trying to check connection with mail server - Problem connecting to mailbox.

The version is 9.2 Build 9225

Outgoing mail is functioning properly.

We followed the troubleshooting steps at http://kbase.zohocorp.com/kbase/ServiceDeskPlus/TroubleShooting/file_100004.html

1. Ports are not being blocked by antivirus or firewall

2. Certificates are installed.

3. N/A, there are no authentication issues

4. N/A

5. N/A

The inbox of the account is accessible through an Outlook client, so we know it is functional.

Support file attached.

Has anyone else experienced this?