Why are emails sent to client from a CRM user visible to all other CRM users?

Why are emails sent to client from a CRM user visible to all other CRM users?

Zoho has quite sophisticated settings to set up users within Roles and Groups to control what data users can view or edit.

This has enabled us to have separate departments on Zoho only seeing the data that they should see.

But there is a big problem (for us) because if a user from one department emails a client (using the CRM) then all other users in any department can see that email.

In short there is not privacy settings at all for client emails - all users in your organisation will see all emails to a client.

I think that zoho should look to fix this issue and offer the same privacy settings for CRM emails as the settings they offer for Mail Add on emails (through POP3 or IMAP).