Within my organization, there are employees with the same name, at different sites. We have changed their display names to reflect their geographic locations, but this does not prevent our users from sending to the wrong person. We need to prevent users at Site 1 from contacting the employee at Site 2. Is there a way to go about this, either by blocking Site 1's subnet / IP range from that specific recipient at Site 2? Or would this be better accomplished with a group policy to prevent outgoing mail from our site to that specific user? Any advice on this would be greatly appreciated.

Hello, you can set a prevention in the properties of the mailbox. In the "mail flow settings" there's a point "message delivery restrictions" in which you can add the users who should not be able to send mail to this specific user. Another option would be to configure a forwarding address to the user at the other site and vice versa. Every mail will then be forwarded to the user in the other site. You can also set an option to deliver the message to the mailbox and additionaly to send a copy to the target's address. You can find this option in the mailbox properties under "mail flow settings" -> "delivery options". I hope i was able to help you. Greetings, Toni

Thanks for the quick response! Unfortunately I'm still somewhat new to this, is it safe to assume a DL can be added to the message delivery restrictions?

Hello, yes, that's possible. Greetings, Toni

Awesome. Does that restriction apply to unwanted messages received over Communicator as well? That seems to be the biggest problem here.