Hi there! My problem is the following: We have a distribution group with the addresses name@domain1.de and name@domain2.de. It works fine. Now we want to split this into two distribution groups since the different domains should be transported to different users. Something like DG1: name@domain1.de to userABC and DG2 name@domain2.de to userDEF I just created the second distribution group and set it up like the first one (and removed the name@domain2.de address from the first DG). But somehow exchange always replies with an error mail "user unknown" when i mail to the name@domain2.de address. I thought maybe i have to wait some time till exchange registers the changes, but that didn't solve anything. Am i missing some transport configurations or something with the distribution group? (All addresses in just 1 distribution group are working fine so i guess there shouldn't be a problem.) I admit i'm not very familiar with exchange so a newbie friendly answer would be nice :) We are running Exchange 2007.

Hi, Are u trying to send email from an external email address (which doesnt exist on your exchange server) When u recieve error on sending email to distribution group ? If this is the case then make sure that "Require that all senders are authenticated" checkbox is unchecked in distribution group properties in Exchange Management Console. Regards,Laeeq Qazi|Team Lead(Exchange + Sharepoint + BES + DynamicsCRM) www.HostingController.com

Ah this solved everything. Thanks! I kinda feel blind not see that option.