Deling with NDR on group
I am an IT manager at a large law firm and have been Running in mixed mode 2007/2003 for about 9 months. Our AD/Exchange environment is used, to some extent, as a listserv for clients and other firms. We host several thousand email lists which contain external user accounts so that case teams from different organizations can communicate easily. With the move the Exchange 2007, the way that non-delivery reports (NDR) changed when speaking of groups. If all eariler versions of Exchange, If I send an email to a group, and one of the addresses in the group generates an NDR, the NDR goes back to ME as the sender. In Exchange 2007, this functionality has changed so that the NDR now goes back to the entire group. This caused a lot of confusion since users are now getting an NDR for an email they did not send. The user, naturally, replies back to the group saying they did not send the failed message, which then generates another round of NDR messages.Exchange 2007 does give an option to change the NDR functionality to not send NDR at all, however I have found that this setting tends to get the outgoung messages blocked as SPAM, specifically but frontbridge spam filtering.Are there other suggestions on how can I organize my directory/groups to avoid these problems?
January 26th, 2010 5:26pm

On Tue, 26-Jan-10 14:26:09 GMT, Chuck_De wrote:>I am an IT manager at a large law firm and have been Running in mixed mode 2007/2003 for about 9 months. Our AD/Exchange environment is used, to some extent, as a listserv for clients and other firms. We host several thousand email lists which contain external user accounts so that case teams from different organizations can communicate easily. With the move the Exchange 2007, the way that non-delivery reports (NDR) changed when speaking of groups. If all eariler versions of Exchange, If I send an email to a group, and one of the addresses in the group generates an NDR, the NDR goes back to ME as the sender. In Exchange 2007, this functionality has changed so that the NDR now goes back to the entire group. This caused a lot of confusion since users are now getting an NDR for an email they did not send. The user, naturally, replies back to the group saying they did not send the failed message, which then generates another round of NDR messages.Exchange 2007 does give an option>to change the NDR functionality to not send NDR at all, however I have found that this setting tends to get the outgoung messages blocked as SPAM, specifically but frontbridge spam filtering.Are there other suggestions on how can I organize my directory/groups to avoid these problems? Exchange 2007 offers three choices:.. Send delivery reports to group manager.. Send delivery reports to message originator.. Don't send delivery reportsThose are the same choices that were available in Exchange 2003.Are the messages being sent by an individual? Or are the messagesbeing sent by someone with "Send-As" permission on the group that'ssending the email posing as the group?---Rich MatheisenMCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP
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January 26th, 2010 8:32pm

The messsages are sent by an individual to a group as a normal email. I dig some heavy digging and apparently my challenge is due to a redesigned policy/process in how Exchange defines the FROM field in the envelope header on forwarded messages. Any message sent via a group is considered forwarded, so the default is to set the FROM to the group name. So when the NDR goes back to the FROM field, it is sent to the group. Changing the group settings to Do Not Send NDR sets the envelope sender to <>, which is often flagged as SPAM.I am not sure if this systems allow links to other pages, but the link below explains in great detail what is happening and why.http://exchangeshell.wordpress.com/2009/09/05/forwarding-exchange-2003-exchange-2007/
January 27th, 2010 6:16am

On Wed, 27-Jan-10 03:16:48 GMT, Chuck_De wrote:>The messsages are sent by an individual to a group as a normal email. I dig some heavy digging and apparently my challenge is due to a redesigned policy/process in how Exchange defines the FROM field in the envelope header on forwarded messages. Any message sent via a group is considered forwarded, so the default is to set the FROM to the group name. So when the NDR goes back to the FROM field, it is sent to the group. Changing the group settings to Do Not Send NDR sets the envelope sender to <>, which is often flagged as SPAM.I am not sure if this systems allow links to other pages, but the link below explains in great detail what is happening and why.http://exchangeshell.wordpress.com/2009/09/05/forwarding-exchange-2003-exchange-2007/ I'm not sure I agree with that. The link explains what happens withredirected messages (not forwarded messages). When a message isredirected it's necessary to preserve the original sender but also toadd the originally intended recipient to the message. The use ofSender Policy Framework and SenderID make this necessary.If a message is sent from a@a.com to b@b.com, and that message isredirected to c@c.com, you'd want the "From:" header to keep theoriginal a@a.com. But if you did that, and that alone, then themessage would arrive at c.com butit would use the IP address of b.com.If c.com is using SPF or SenderID and a.com publishes a SPF recordthen the message would be seen as having a spoofed address.To circumvent that, an additional header (it may be be "Sender:", orone of the "Resent-*:" headers) is inserted into the message with theb@b.com address. Now the message arrives from the IP address of b.comand the MAIL FROM says it's from b@b.com.I tried sending a message to a DL with two members. One that I knowexists, and the other that I know doesn't exist. I sent e-mail to theDL three times, each time with the delivery report set to a differentchoice. The SMTP log always shows the MAIL FROM address to be mine.I don't think the MAIL FROM is ever set to the null address "<>" inthis situation.Where did you see that "MAIL FROM:<>"? Was it in the SMTP protocollog? If you're using an edge server there will be two such entries --one for the outbound mail to the target server(s) and one for the NDRto the Hub Transport.In either case, I think that the correct thing to do is to have thedelivery reports sent to the group owner. It's that person'sresponsibility to keep the group membership current, not the personthat sends the email.---Rich MatheisenMCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP
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January 27th, 2010 7:46am

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