IMAP syncing problem AGAIN

IMAP syncing problem AGAIN

My employee's IMAP has stopped working again. 

It gives a message "Your IMAP server wants to alert you to the following: Your account is blocked from further IMAP use.  this is caused due to excessive IMAP usage.  For further clarification please contact support@zohomail.com."

He only has 1 zoho email address and downloads to his computer and phone. 

Why does this keep happening?

His account is garygarrett