I setup a new distribution group and checked the box under message delivery restrictions "Require that all senders are authenticated", however email is being delivered from the internet. Any ideas on what is happening here ? Thanks Exchange 2007 Rollup 5 SP1

If you query the DG using the EMS, do you see the restriction there? Get-DynamicDistributionGroup MyGroupName | fl require* Alexei

If you query the DG using the EMS, do you see the restriction there? Get-DynamicDistributionGroup MyGroupName | fl require* Alexei If distribution group is normal ,not dynamic, then correct command is: Get-DistributionGroup MyGroupName | fl require* Regards,Laeeq Qazi|Team Lead(Exchange + Sharepoint + BES + DynamicsCRM) www.HostingController.com

Restart Transport Service. That often fixes things like this. I don't think that property is cached by Exchange. Does your email come in direct, or through another service. That can sometimes confuse things. Simon.Simon Butler, Exchange MVP. http://blog.sembee.co.uk , http://exbpa.com/

Hi, Barnold997, Firstly Could you confirm whether the email come from the authenticated user or not? Secondly, I suggest you check properties of your DG by using EMS. By using “Get-distributiongroup DLname | fl” or ” Get-DynamicDistributionGroup Dlname | fl” to get detail information. Verify the “RequireSenderAuthenticationEnabled” parameter was set “true”, if the value is “true” which means messages are accepted only from authenticated senders. You can get details from : http://technet.microsoft.com/en-us/library/bb124955(EXCHG.80).aspx Thirdly, please check property of receive connector, in the “Authentication” tab, verity the “Externally secured” option. When the checkbox was selected, Exchange will Consider any client able to connect server. By the way, another point which should be mentioned is that a newly created recipient may not receive email messages for up to 4 hours, Check the information from here : http://support.microsoft.com/kb/961303

Restart Transport Service. That often fixes things like this. I don't think that property is cached by Exchange. Does your email come in direct, or through another service. That can sometimes confuse things. Simon. Simon Butler, Exchange MVP. http://blog.sembee.co.uk , http://exbpa.com/ Have the same problem, and look into many things/settings (took around 4 hours (and counting) to solve it), tried to restart the transportservice. Tried to execute the command what mentioned here, and the setting of the distributiongroup: RequireSenderAuthenticationEnabled : True. I've only a thought about the 'mail through another service'; we use a pineapp to filter most of the spam before it reaches Exchange, but it did work after installing it, only not now for some weeks. Tonight I'll reboot the server and hope it'll work again, but I've some hard thoughts about that.

It seems the latest Rollups (3 and/or 4 for SP2) have screwed up these settings to make it work. Is there any idea how to fix this problem? It's getting annoyed now since it doesn't work like it should do.