Hi,We have a single user who randomly received NDR messages when sending toour externalPR company. No-one else has receveis the NDR's just this particular manager.Current setup:Exchange 2003 SP2, Outlook 2007 the manager's mailbox is also open on his assistant's machine which is also running outlook 2007. The managers mailbox is around 6gb in size and the assistants mailbox is just under 2gb.I often receive system errors stating that the assitant's mailbox has exceed the maximum number of session open (500) and wonder if this has anything to do with it. I have researched the NDR and found links to the mail format being blocked by the recipient (not the case), the emails which bounce back have the from field as blank. however cant seem to find the root cause of the field being blank.The NDR is shown below: Your message did not reach some or all of the intended recipients. Subject: Subject Sent: 24/07/2009 16:57 The following recipient(s) cannot be reached: user@emailladdress.com on 24/07/2009 16:57 None of your e-mail accounts could send to this recipient. Any help would be appreciated.

Hi Leeifer2, Can you please paste the NDR over here? or i would like you to check the header information of outgoing mail from NDR. also check the Header of the NDR to verify that the NDR came from the same org where you sent mail. Let me know. Thanks.Vishal Ramnani | MCITP - Exchange 2007 | MCSE Messaging

Hi Vishal,THanks for the reply. I copy and pasted all the information from the NDR email that i have. I noticed in exchange 2007 you get diagnostic information but in 2003 this is not displayed. (http://technet.microsoft.com/en-us/library/bb232118.aspx)As i have pasted it about is all the information included on the NDR?THanks

It is not a good practice to allow MB to grow up to 6GB. and also could you also let us know Email NDR's only when you send email to one particular external domain or you get NDR from random domains as well? Vinod |CCNA|MCSE 2003 +Messaging|MCTS|ITIL V3|

Leeifer2, Also Please copy and paste the Header information from that NDR. Thanks.Vishal Ramnani | MCITP - Exchange 2007 | MCSE Messaging

I know, I have told the manager that is not helping matters. But as they are very senior, I am fighting a losing battle! We used to make do with limits of just 100mb but someone de-limited this account.Yes, only seems to NDR when emailing our PR company on external domain. And only this user. All other email they send gets delivered to other external domains without problem.

Hi,Not sure where to get the header information from. As mentioned above, I have searched for it but could only find for 2007 and not 2003?

Hi,I am agree with Vinod.As you mentioned error "mailbox has exceed the maximum number of session open" this is not related with NDR you recive to send message to any recpeints.Generally this error get when you use so many add-ins in outlook so outlook make so many connection with outlook.Anil

Would it be possible for you to launch his OL with /cleanrules switch? and then do some testing? Vinod |CCNA|MCSE 2003 +Messaging|MCTS|ITIL V3|

Who is sending the message the assistant or the manager? Do either have any custom contacts for this external email address in Outlook? This looks like a partial ndr, can't determine who the reporting server is, your exchange or their mail server. The next thing you need to do is examine the SMTP logs to see if you see the session and the SMTP failure code. You may also try to take the users out of cached mode if they are for a few days to see if the error comes up. James Chong (MVP) MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Follow the instructions. http://www.abika.com/Reports/Samples/emailheaderguide.htm Thanks.Vishal Ramnani | MCITP - Exchange 2007 | MCSE Messaging

The manager is sending the emails not the assistant. And they are not using any contact lists or groups, just typing in the email address manually. Not sure when Ill get the chance to try the /cleanrules switch but will give it a go. I had a look at the link but there are no header details. There are on other emails but not on the NDR? It seems that any sent emails do not have any header info, only received emails. Perhaps this suggests it is our exchange server causing the problems? The NDR is not incomplete, that is all the information there is?

Does your manager possibly have multiple profiles like IMAP or POP that he may be inadvertently using at times?James Chong (MVP) MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

in many cases i have seen, there are chances of Backscatters which are Valid NDRs. when Spammers send thousands of spams by using someone else ID, many times the spoofed ID get NDRs if recipient does not exist. Please let us know about the NDRs you get are from multiple domains or a single domain? if it is from multiple domains, these could be BackScatters. There are two ways to block them. first one is to completely block all NDR at edge by putting some email rules (which is not recommended) or stamp a signature on all outgoig mails in Return-Path and verify bounce mails with signatures (need to use some third party tools such as ProofPoint).Vishal Ramnani | MCITP - Exchange 2007 | MCSE Messaging

Hi, I suggest you attempt the following method to check the issue: 1. Whether the issue can be reproduced? 2. If the issue can be reproduced, please open the Sent Items of the user's Outlook, and check the sent message, does the From field is Blank? 3. Please run Outlook in safe mode and check if the issue occurs again:a. Click Start->Run, type "Outlook /safe" (without the quotation marks) and press Enterb. Send message and check if the issue occurs 4. If you send the message by using OWA, whether the issue can be reproduced? 5. If you rename the Nk2 file on managers computer, have the manager type the email address manually, whether the issue can be reproduced? Mike Shen TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com

Hi, Any update regarding the issue?Mike