Email Policy

Hello,

I am not sure if Zoho Email System can do what I am trying to do without setting up an actual Exchange Server, I have a need to block users from sending emails outside their email domain, so if a user tries to send an email or forward an email to anything outside his Org he should get a non delivery or access denied message. Is that doable with Zoho? or is there any add-on that can accomplish this need? Or any other email hosting service out there that can support this "feature"

Thanks,
J.