Large emails not arriving RRS feed

  • Question

  • hi,

    My company sends and recives alot of email to/from clients. many of these files carry large attachments but recently i have been informed that emails from clients are not arriving.

    These emails can have attachments of 8MB or more and the client doesnt recive any bounceback or failed notices

    we are using exchange 2007 and i wanted to know if there was any programs or tools that would let me send test emails with large attachments to see where the emails are being stoped or if anyone has any ideas what is causing the problem

    Friday, February 10, 2012 8:39 AM

All replies

  • First check what is attachement size defined in your exchange enviornment. If it is less than 8MB then please have it increased to 10 MB.

    Refer the following link which explain how to increase the attachement size Limit.




    By Default Exchange has Tools Tab from which you can check the flow of your organisations email.

    Please refer these links for better understanding





    MCSA|MCITP SA|Microsoft Exchange 2003 Blog - http://prashant1987.wordpress.com

    Friday, February 10, 2012 10:00 AM
  • ive looked at those threads before, our size limit is set to about 20Mb
    Friday, February 10, 2012 11:22 AM
  • Please check this link:


    Can you help me with the version of Outlook client and the NDR message that you recieve while you try to send Emails with attachments ?


    Deepak Exchange 2003/2007/2010

    Friday, February 10, 2012 3:02 PM
  • Also please check the Transport settings on the Exchange Management Console

    Server Configuration > Hub Transport Role > Global Settings > Transport Settings > Check the Maximum Send/Recieve settings.


    Deepak Exchange 2003/2007/2010

    • Proposed as answer by Terence Yu Monday, February 13, 2012 2:54 AM
    Friday, February 10, 2012 3:04 PM
  • You must enable / increase the attachment size on the Global Settings as Deepak mentioned.

    If you do use smart host server then you might wanna look at the smart host panel too and change the settings in your exchange as well.

    And also do remember whatever the attachment size you want to allow always add 34% addtional to that becuase of TCP headers and other information. Let say if you want to allow 20MB to the users then on the server you must allow approx 27MB.

    Where Technology Meets Talent

    • Proposed as answer by Terence Yu Monday, February 13, 2012 2:54 AM
    Friday, February 10, 2012 9:56 PM
  • Since the clients aren't getting an NDR, it sounds like the emails are being accepted. 

    If you don't have it enabled, enable smtp protocol logging on the boundary servers, and check those logs to verify that the emails are being accepted.  You should be able to see the sender, recipient and message size for each message in the logs using verbose logging.  If you establish that they are being accepted, pick one and start tracking it through the message tracking logs.

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    • Edited by mjolinor Friday, February 10, 2012 10:05 PM
    • Proposed as answer by Terence Yu Monday, February 13, 2012 2:54 AM
    Friday, February 10, 2012 10:05 PM
  • Hi Netallix25
       Do you modify all setting of attachment limit?
       Can you post your result ?

    Terence Yu

    TechNet Community Support

    Monday, February 13, 2012 2:56 AM
  • we are using outlook 2003, the max send/recive size on is 24mb.
    Monday, February 13, 2012 8:22 AM
  • ive checked the logs, the missing emails dont even seam to be arriving at the server.
    Monday, February 13, 2012 8:26 AM
  • Hi 
       Maybe you should check your network device setting. (firewall,router)

    Terence Yu

    TechNet Community Support

    Monday, February 13, 2012 8:33 AM
  • already checked, from what i can see the firewall isnt blocking anything from what i can see
    Monday, February 13, 2012 8:35 AM
  • Hi
       AS far as I know, windows default won't block email.
       Maybe you should inquire you AV vendor.

    Terence Yu

    TechNet Community Support

    Monday, February 13, 2012 9:00 AM
  • ive considered that, but with the files not arriving at the server the AV shouldnt be blocking it.
    Monday, February 13, 2012 9:50 AM
  • Hi
       Do you find any error on your client or outlook ?

    Terence Yu

    TechNet Community Support

    Tuesday, February 14, 2012 12:49 AM
  • no, no error messages of any kind which in of its self is a problem.

    Clients are sending us important information and when we inform them that the email didnt arrive they get funny about resending it. i've checked the logs and they arent even registered as reachign the server

    Tuesday, February 14, 2012 8:06 AM