Once Exchange server is upgraded to a newer version, at times email sending from SM to Exchange stops working.
1. First of all it is necessary to find out what is the utility used to send emails from SM. Usually there are four ways to send out emails from SM :
a. SCMail/Emailout - This requires smtp connection details in sm.ini
b. scsmtp exe file - This requires scsmtp.ini with SMTP connection details
c. ScAuto Mail - This requires scmapi.ini to have Outlook profile details.
d. Connect-It - This requires the Email connector to have SMTP details or Outlook profile details.
2. Check if the new Exchange server version is supported or not.
3. Check if the Exchange client installed on the SM/CIT side is same as Exchange server or not. If not then make sure the versions are same and supported.
4. If outlook profile is used then it gets corrupted often. Try to delete and recreate the profile under control panel.
5. Install an Email client to check if the emails can be accessed via the client.