Hi, I am new to Zoho. 

Sometimes inside email section I can see emails that are sent from account that we are using inside our company (from that account we are sending meeting invitations to our contacts).

Inside emails section, I can see from which account they are sent, to whom they are sent, but when I try to open these emails I am getting the message:

"We're unable to process your request as there is an issue with Adam Smith's IMAP configuration."

Adam Smith is our ex employee (he is not a contact), and he was working as Zoho CRM administrator.

How can I solve this problem?

Is there some course/tutorial on the internet where I can find how Zoho emails are functionating? 

Can you also recommend me some good Zoho courses/tutorialas?