I created a mail enabled universal distribution group(s) in Exchange 2007 sp1 running on Windows Server Std 2008 and have added valid email users to the group. However, I am unable to send email to this group. In OWA, I get the following error and the message will not send:ExceptionException type: System.ArgumentNullExceptionException message: Value cannot be null. Parameter name: itemStoreObjectIdFrom Outlook 2003, the NDR contains:#550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ##Other, older distribution groups work fine. No error messages in event logs...we simply cannot send mail to this or any new distribution group.Thanks,JS

Looks like it didnt got updated in the AD. The NDR cleary says "RESOLVER.ADR.ExRecipNotFound".Can you check the domain parttion in ADSIEDIT and drill down till this DL and see if it has been updated properly.Also try to create another test DL with some valid users and see if that works.Raj

That's what I thought when it first happened. I created another group with valid users once I determined that the first one had failed...with the same response. I drilled down through all the adsi settings in both new groups (before I sent the post) and compared the settings to known good mail enabled distribution groups. No luck. Here is the address that it thinks it is: IMCEAEX-_O=NT5_ou=32hexdecnumberhere_cn=32hexdecnumberhere@mydomainnameGot it!!! I THOUGHT I had looked at every setting. For some reason, it was missing information in the legacyexchangeDN field. My clients still use Outlook 2003 and this field needs to be populated. I did set and reset the expansion server in an attempt to resolve this so if the first issue does not fix the problem, try the second as well.It's always something different....Thanks for your response.

See if this helps http://www.experts-exchange.com/Software/Server_Software/Email_Servers/Exchange/Q_24185173.htmlRaj