Hi Mohsen

The enable the Exchange Server option (used for synchronising Diaries) is under System - System Behaviour and then "Use Exchange Integration" 

As for the alert, whilst the logs show the emails have sent, are they actually in CRM? e.g. If emailing about an Opportunity, a copy of the email would appear under the opportunity (unless do not file is ticked). 

I have seen this before, and in our own system have had to set up a big workaround where I want to send an alert.... but I also have a stored procedure in place where the condition to fire the email is met, and I have a 'stop field which is updated when the email is sent. But in order to update the stop flag, I have the Escalation I) Fire off the email II) Checks the communications for an email with the subject line I want - can't rely on the record ID as the communication doesn't necessary file against the record. III) If the communication is found, to update the stop flag so it doesn't fire the email again, otherwise if the communication isn't found it allows the email to fire and then rechecks. 

Very long winded, but it works. Have put in an enhancement request for CRM to naturally confirm within itself that it has actually sent an email. rather than just fire and forget. 

Thank you for your response. I was able to enable Exchange, but I don’t think it helps in my case at the moment.

The Do Not File option is enabled, so I can’t see the emails within CRM.

Regarding the procedure you mentioned, all of that had already been implemented by the developers, and the emails were working fine before. The issue started after the migration to Microsoft 365.

It seems that the settings under Email and Documents are only for sending emails directly from CRM, while the alert emails are configured within the workflows. I can see the email actions there, but unfortunately there are no specific settings related to Microsoft 365.