We have a distribution list with over 700 recipeients, some internal, some external. When a meesage is sent to this list, some of the external recipients do not recieve the message. According to both our message tracking and the SMTP gateway at the reciepients end, the message is going out with a Null sender and is therefore being blocked or dropped on the other end. Is there a setting In Exchange Server 2003 that will force the outbound message to contain the sender info?

Check to see if the users that are being dropped are hidden from address lists.Andrea

Hi, Would you please let me know whether the option "Send delivery reports to message originator" is selected for the distribution group. According to following article: Selecting "Do not send delivery reports" disables the sending of read receipts for mail-enabled groups http://support.microsoft.com/kb/271419 When you have the “Do not send delivery reports” setting selected on a distribution list, we use the return path <>. The reportToOriginator attribute is set to False to prevent someone from sending a message with request for delivery report to a distribution list. When the server tries to send back the delivery report to the sender, it does not send that information back. The From field is blank for two reasons: To prevent outside user from finding the members on a distribution list. To prevent a possible mail storm to that Distribution list and to its members. ~~~~~~~~~~~~~~~~Mike Shen TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb @ microsoft.com ~~~~~~~~~~~~~~~~~

The option to Send Delievery reports to message originator is selected.

They are not being hidden from the address list. The user that are having this problem though are setup as users in AD but there email resides on the State network. See below...the return path is <>Microsoft Mail Internet Headers Version 2.0Received: from ADMEXCH.mydomain([10.xxx.xx.xx]) by hhsexch.mydomain with Microsoft SMTPSVC(6.0.3790.3959); Mon, 12 Oct 2009 12:43:52 -0500X-MimeOLE: Produced By Microsoft Exchange V6.5Content-class: urn:content-classes:messageMIME-Version: 1.0Content-Type: application/ms-tnef; name="winmail.dat"Content-Transfer-Encoding: binarySubject: INTER-OFFICE ENVELOPESDate: Mon, 12 Oct 2009 12:43:45 -0500Message-ID: <EMAIL GONE>X-MS-Has-Attach: X-MS-TNEF-Correlator: <EMAIL GONE>Thread-Topic: INTER-OFFICE ENVELOPESThread-Index: AcpLY4vVw3q2GPcEQjC6rMZSOXGShw==From: "Michael McGuire" user@mydomainTo: "All Downtown County Employees" All_County@mydomainReturn-Path: <>X-OriginalArrivalTime: 12 Oct 2009 17:43:52.0744 (UTC) FILETIME=[90400280:01CA4B63]

Hi, I am not able reproduce your issue if the Distribution Group is configured to “Send Delievery reports to message originator”. At this time, would you please let me know whether the Distribution group works previously? If you create a new Distribution Group and add the problem external recipients to the Distribution Group, whether the issue can be reproduced when sending email to the new Distribution Group? I also suggest you enable SMTP Protocol log on the SMTP Virtual server. Please check whether the sender address is blank when type Mail From command in SMTP session: If the sender address is blank, you should get log like below: 2009-10-15 14:05:27 192.168.1.1 OutboundConnectionCommand SMTPSVC1 BE2 - 25 MAIL - FROM:<> 0 0 4 0 60 SMTP - - - - Thanks, Mike

Hi, Any update regarding the issue?Thanks,Mike

This fixed our issue. Alerts from our monitoring system were not making it through to my cell phone as text messages. Our Barracuda showed that the sending address was blank for the outbound message to %phonenumber%@messaging.sprintpcs.com. I'm getting these alerts as texts now.