Hi Guys, We have a distribution group setup with 4 internal users and 2 external contacts. this list works fine around the office, but when one of the external contacts (or any external contact for that matter) tries to send to this list a bounce back message is recieved for the 2 external contacts. Final-Recipient: rfc822;mcservicedesk@gmail.com Action: failed Status: 5.5.0 Diagnostic-Code: smtp;550 Administrative prohibition - envelope blocked X-Display-Name: servicedesk To get around this we thought we could create 2 AD accounts and have them auto forward to the contact cards. we added the AD accounts to the DL but we still recieved the same error. Is it possible for an external user to send an email to an Internal distrubtion list that contains external contacts? Hope i have provided enough information.

Hi, Goto properties of the Distribution Group in Exchange Management Console and uncheck the property "Require that all Senders are Authenticated" and then check mail flow. You can also do it using powershell command set-DistributionGroup "DGName" -RequireSenderAuthenticationEnabled $false Regards,Laeeq Qazi|Team Lead(Exchange + Sharepoint + BES + DynamicsCRM) www.HostingController.com

This is in Exchange 2003, i dont think i have this option in the Exchange system Manager.

This is in Exchange 2003, i dont think i have this option in the Exchange system Manager. Yes you have in ESM 2003. Plz check the properties of the DG and see "Require that all Senders are Authenticated" attirbute and unselect it. Regards,Laeeq Qazi|Team Lead(Exchange + Sharepoint + BES + DynamicsCRM) www.HostingController.com

all that i can see is the MEssage Restrictions - Accept message from Everyone. Authenticated users was already unticked.

can anyone help with this? there is no option in Exchange 2003 that enables me to deselect REQUIRE THAT ALL SENDERS ARE AUTHENTICATED

Please check the contacts for the same setting.

can anyone help with this? there is no option in Exchange 2003 that enables me to deselect REQUIRE THAT ALL SENDERS ARE AUTHENTICATED This is the excerpt from an MS document: Microsoft Exchange Server 2003 has a new feature that permits mailbox users or distribution groups to only receive e-mail messages from authenticated users. This feature permits you to restrict inbound Internet e-mail for specific users or for distribution groups. The feature is enabled when you click to select the From authenticated users only check box in the Message restrictions settings for an individual user or a distribution group Plz see this to disable this property for exchange 2003 DL: http://support.microsoft.com/default.aspx/kb/827616?p=1 Have you performed following steps: Click Start, point to Programs, point to Administrative Tools, and then click Active Directory Users and Computers. Right-click the distribution group, and then click Properties. Click the Exchange General tab. Under Message restrictions, uncheck From authenticated users only check box. Regards, Laeeq Qazi|Team Lead(Exchange + Sharepoint + BES + DynamicsCRM) www.HostingController.com

I dont get it. Is the option "Only from authenticated Users" enabled and you cannot desselect the option?