I would like to disable a Zoho Mail account from our organization without deleting it so that CRM data of that user is not lost. Is there a way to do this?

I know in CRM there's the option to do it but on the Mail Control Panel I only see the option to delete the account. 

The account is of an employee no longer working for us and we don't need the emails from that account, we only need to be certain that none of her CRM records will be deleted.

Can you help me figure out how to do this please?

Thanks!