Fix Mail-crash when using Exchange Connector
If your apple mail crashes randomly on your iMac, it could be that mail is conflicting on old settings. To solve this issue do the following:
If you should have this after you followed above steps, go into your Internet Accounts Settings and check the Exchange Accounts. Uncheck Reminders & Notes and start your Mail APP again.
Go to the Account Settings in Mail, select you Exchange account, go to tab Server Settings than, Advanced Exchange Settings. Turn off “Allow insecure authentication” and select “None” for the TLS Certificat.
That's it!
Enjoy,
Your ArtIT Team