Bug? Email sent to contact from zoho Mail add on not shown in CRM

Bug? Email sent to contact from zoho Mail add on not shown in CRM

I have the zoho Mail add on configured with a pop account. I sent an email to a contact's email address through the Mail add on but it doesn't appear under the list of emails in the contact's record in the CRM. Surely this is a bug? Have I got anything configured incorrectly? Thanks!