Hi, I have an Exchange 2010 in my environment with test.local domain for internal and test.com for emails and I would like to know if that is possible: - I want that some users can not receive external emails, just internals. For that I am thinking of create a Distribution Group, insert the users in it, erase the @test.com address and leave @test.local in it. So users can receive and sen internal emails Is that right? Thanks for while. Luiz

Hi Luiz The easiest way to achieve this (assuming all your internal users are Exchange) is to tick the "Require that all senders are authenticated" box. Mailbox Properties -> Mail Flow Settings -> Message Delivery Restrictions. Running this command will have the same effect: Set-Mailbox username -RequireSenderAuthenticationEnabled $True Cheers, Steve

Hi Steve, but the users can send and receive emails internally? Thanks for the help. Best Regards. Luiz

Yes, internal Exchange users are authenticated to Exchange but anyone external is not.

Thank you again, Steve. Best Regards. Luiz