Hello everyone, I have a situation where a user is not receiving some mails from a few colleagues in the same company (ie.all mailboxes on the same Exchange 2007 server). The mails weresent to several internal recipients, but only one did not receive it. Other mails before and after have been delivered successfully to him, but a number have not. The weird thing is, if I go into the Message Tracking Tool, there is an event ID of DUPLICATEDELIVER from source STOREDRIVER next to the mails which are not being delivered. If I do some internet digging around, I can't find anything about an event ID DUPLICATEDELIVER, it doesn't appear in the dropdown list of events in Message Tracker, and the TechNet documentation about Message Tracker doesn't seem to think it exists either. Can anyone shed any light on this? Thanks, Pete.

Hi, Duplicatedeliver event occurs if the sender domain is send email with the same message ID to exchange server. By default the duplicate detection is set to 1 hour and these event after generated by store. For more information about duplicate detection, please check below article on Exchange team blog: http://msexchangeteam.com/archive/2004/07/14/183132.aspx regarding your situation, the non delivery mail possibly cause you have some third party mail server, not Exchange server which sending multiple email with same message id to exchange. you may also need to investigate where the group expansion is happen at, Exchange server or some other servers? -Jason

Hi Jason, Thanks for that - most helpful. Just to clarify things though, both sender and recipient are in the same company, and their mailboxes are hosted on the same store on the same Exchange 2007 server. The Exchange server is also a domain controller. I'm not sure if the address list was an expanded group or whether the names were entered individually, but presumably if several groups were expanded with overlapping members then the list would be stripped down to one mail per user? If I use the message tracking tool on the server for everything from an hour before and an hour after the faulting message then all theentries with the same MessageID are the same mail (ie. one e-mail with lots of entries - there isn't a mail coming in from another source confusing the issue). The duplicate detection is set to the default. Am I looking in the right place for information on this or is Message Tracking not the best tool for the job? Pete.

Sorry, I cannot reproduce your situation of undeliverable mail due to the DuplicateDeliver event. You can capture a screenshot to me at v-jassol@microsoft.com regarding the DuplicateDeliver place. I suspect the failed message entry you found in message tracking is not this missed mail for your end user. It may another mail flow from internet outside servers. I suspect that you might not choose the proper event ID and start time and end time to trace the correct message flow. For your reference, Message tracking tool provides us following Event ID for troubleshooting mail flow issue <Receive, Send, Fail,DSN,Deliver,Badmail,Resolve,Expand,Redirect,Transfer,Submit,PosionMessage,Defer> By the way, here is answer to your first question: Yes, If several group were expanded with overlapping members, everyone should only receive one mail per user. I believe message tracking is the best tool for troubleshooting mail flow issue. More Article about Message Tracking Tool ========================================= http://www.msexchange.org/tutorials/Exchange-2007-Message-Tracking-Part1.html http://www.msexchange.org/tutorials/Exchange-2007-Message-Tracking-Part2.html -Jason

Hello Jason, As requested I have sent you a screenshot from my work e-mail account and so feel free to reply either to it or on here. Also, please let me know if there is any further information/views I can give you. Thanks, Pete.

Thanks for your screenshots. I have justreplied you a email with my test result screenshot, please have a look. According to my tests, Duplicate Deliver event cannot be a cause or an evidence for the missing email issue. it should be expectedeventwhile mail flowdetected duplicate mail in detection table. you may do the same test with the userlike in my eamil and try to reproduce the issue,Does the missing email occur again? -Jason

Hi Jason, I'm also experiencing this same problem (seems to be intermittent). Email from outside source to a distribution group. It has been working for about a week (looking at the message tracking results) then the duplicatedeliver from storedriv started appearing and people within the distribution group didnt receive the email. Strangely though, my email address is in the distribution group and I always get the email. Wouldit be possible for me to send you my message tracking results? + get a little help