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Office 2016 attachments not arriving

    Question

  • I'm having a strange issue with Outlook 2016, with an Office 365 back-end. When I send an email with an attachment over 3 MB in size, the recipient does not receive the attachment, and no notification is given. In addition, the graphic in my signature "breaks" (replaced with placeholder).

    Notes:

    1) This does not happen with Office 2010.

    2) This happens with new 2016 installs on fresh PC (no other software installed, i.e. AV)

    3) This does not happen with the web mail client.

    4) This happens irrespective of RTF/HTML settings on the client or tenant.

    5) Multiple users are affected.

    6) Email size limits on the tenant are set to 100 MB.

    7) Attachments under approximately 3 MB work just fine.

    8) Emails sent between tenants are still affected.

    Does anyone have any suggestions? This is a strange one.

    Wednesday, October 04, 2017 8:45 PM

Answers

  • Hi all,

    The Outlook Team identified the root cause of the issue and was able to turn off the functionality causing it on the service side.  To pick up the change please restart Outlook.  Please monitor and let me know if you see any new reports of the problem now that the change was made in the flighting.  

    Tuesday, October 17, 2017 11:19 PM

All replies

  • Hi Bulbous,

    >> Multiple users are affected.

    By this, do you mean the attachments sent by these users cannot be received?

    To help narrow down the issue, please go to the Sent Items folder in the sender's mailbox, confirm if the attachment is missing in Sent Items folder.

    Besides, it is also suggested to have a check to see if the "File attachment size limit - Outlook" is set properly:

    https://technet.microsoft.com/en-us/library/exchange-online-limits.aspx#MessageLimits

    Any findings, please post back at ease.

    Best regards,
    Yuki Sun


    Please remember to mark the replies as answers if they helped.

    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.


    Thursday, October 05, 2017 4:38 AM
    Moderator
  • Yes, I mean multiple users are having the issue where their attachments are missing if over 3MB. I suspect it is tenant-wide, but I have not confirmed this yet.

    The attachment is present in the "Sent Items" folder. The Max Attachment message size is set to 100 MB.

    Thursday, October 05, 2017 1:24 PM
  • This issue is tenant-wide.
    Friday, October 06, 2017 2:48 PM
  • Hi Bulbous,

    Sorry for the delay.

    Could you please have a check at the Internet header of the problematic messages and see if it has the field below:

    X-MS-Has-Attach: yes

    Best regards,
    Yuki Sun


    Please remember to mark the replies as answers if they helped.

    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.


    Friday, October 13, 2017 9:43 AM
    Moderator
  • Thank you. That particular header has no value, i.e.:

    X-MS-Has-Attach:

    Some further troubleshooting indicates that only Outlook 2016 version 1708 is affected. Versions 1707 and earlier are not affected, and one workaround for the problem is rolling back to an old version. In addition, only certain attachment types (i.e. .txt) are affected.

    I actually suspect that this problem is universal, so if anyone can verify that would be very helpful! If you have Outlook 2016 Version 1708 or newer, just email yourself a 4MB .txt attachment!

    Post your results here.

    Friday, October 13, 2017 2:32 PM
  • Thank you. That particular header has no value, i.e.:

    X-MS-Has-Attach:

    Some further troubleshooting indicates that only Outlook 2016 version 1708 is affected. Versions 1707 and earlier are not affected, and one workaround for the problem is rolling back to an old version. In addition, only certain attachment types (i.e. .txt) are affected.

    I actually suspect that this problem is universal, so if anyone can verify that would be very helpful! If you have Outlook 2016 Version 1708 or newer, just email yourself a 4MB .txt attachment!

    Post your results here.

    Yes, seeing the same thing here. Upgraded to 8431.2107 and the issue continues.

    P.S. OWA seems to work fine.

    Friday, October 13, 2017 2:35 PM
  • Hi all,

    We were able to get an internal repro and the Outlook Team is investigating.  I'll post back when we know more.

    To work around the issue on Monthly Channel/Current use the following steps to revert to an earlier version:

    1. Open a command prompt window.

    2. At the command prompt, run the following commands sequentially:
    cd %programfiles%\Common Files\Microsoft Shared\ClickToRun\
    officec2rclient.exe /update user updatetoversion=16.0.8326.2107

    If you are on Semi-annual/FRDC use these builds:

    1. Open a command prompt window.

    2. At the command prompt, run the following commands sequentially:

    cd %programfiles%\Common Files\Microsoft Shared\ClickToRun\

    officec2rclient.exe /update user updatetoversion=16.0.8201.2158
    or
    officec2rclient.exe /update user updatetoversion=16.0.8201.2171

    Tuesday, October 17, 2017 8:20 PM
  • Hi all,

    The Outlook Team identified the root cause of the issue and was able to turn off the functionality causing it on the service side.  To pick up the change please restart Outlook.  Please monitor and let me know if you see any new reports of the problem now that the change was made in the flighting.  

    Tuesday, October 17, 2017 11:19 PM
  • Hi Gabriel.

    Thanks for sharing the information above with us!!

    Best regards,
    Yuki Sun


    Please remember to mark the replies as answers if they helped.

    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.


    Wednesday, October 18, 2017 4:57 AM
    Moderator
  • The Outlook Team identified the root cause of the issue and was able to turn off the functionality causing it on the service side.  To pick up the change please restart Outlook.  Please monitor and let me know if you see any new reports of the problem now that the change was made in the flighting.  

    Looks like the issue is resolved! Thanks!
    Wednesday, October 18, 2017 1:27 PM