Retain Emails for Deactivated User in CRM

Retain Emails for Deactivated User in CRM

I have CRM Plus.  If a sales person leaves, we loose all email history for the Lead, Contact or Account.  That is a major flaw in the product.

I have been told I can take a backup.  There is no way to import email into CRM.  How do we keep the email history that was created by a sales person who has left the company for these entities?