Removing email hosting only

Hello

We have moved our email away from Zoho but are currently still paying the monthly fee for the mailboxes which still retain the old emails, even though the domain's MX is no longer pointing to Zoho.

I need to remove these email accounts and turn off their subscription, but some users are still using Zoho CRM & Projects.

How can I remove the mail accounts (and their contents) without affecting the other Zoho services?

Thanks