Error -19761 when sending mail (The send or update operation could not be performed because the change key passed...)

Anonymous
2016-10-04T16:13:47+00:00

I’m having a problem with one user in our system. Details are as follows:

Platform: OS X 10.10.5

Outlook version: Outlook for Mac 2016 (15.26.1)

Problem: Randomly (about 5-10 times through the work day), when the user sends an email, they get an error in Outlook for Mac, the message is not sent, and the message is put in their Drafts mailbox. The error that is displays is as follows:

The send or update operation could not be performed because the change key passed in the request does not match the current change key for the item., Cannot submit message.SaveStatus: IrresolvableConflict

PropertyConflicts: Mail could not be sent. The message has been moved to your Drafts folder.

Account name: "XXX"

Error: -19761

They then open the message from their Drafts folder and attempt to resend it. It then sends without issue.

Some additional notes:

  • The error started happening 2 days ago—no changes were made to the user’s machine prior to the error appearing.
  • The error happens when sending to both internal and external contacts.
  • The error only happens when using Outlook for Mac desktop client (the issue does not happen when sending mail via OWA or iPhone, etc.)
  • We have updated Outlook for Mac to the latest available version (15.26.1).
  • We have deleted/re-added the account in Outlook.
  • We have uninstalled/reinstalled the Office 2016 package on the computer.

Any advice would be appreciated.

Thanks,

Kristin.

Outlook | MacOS | Legacy Outlook for Mac | For business

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  1. Anonymous
    2016-11-02T17:27:15+00:00

    Hi folks -

    Sorry for the inconvenience.  We are currently looking into this problem.

    In short, the Exchange protocols often perform multi-step processing of requests with multiple saves under the covers.  However, we also have some other internal processes that do auto processing of items within a mailbox when events occur (changes, new mail, the dog barks, etc...).  As the number of "assistants" working in the background increase, the greater the chance that we run into a race condition between these two.  This race condition is why you are seeing this intermittently.  This also explains why you are getting a "Change key stale" error back even though you didn't pass in a change key.

    We are currently working with the appropriate teams to ensure we have a holistic fix for this rather than spot fixing with Band-Aids.  Again, sorry for the inconvenience - we are engaged.

    In the short term:

    1. You are doing nothing wrong.
    2. OLK isn't the problem, so no sense in reinstalling.

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  2. Anonymous
    2016-11-02T18:21:15+00:00

    John,

    Just want to add, I have discovered we are experiencing this issue also. One confirmed user right now.

    Outlook 2011 for Mac v14.6.8

    Exchange Online Plan 1

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  3. Anonymous
    2016-11-03T18:21:56+00:00

    David,

    Can you post a note here when you complete the holistic fix for this issue. We have seen this specific error condition for one user and will probably have to notify all our Mac Outlook users of the potential. I need a way of knowing when this is resolved. Having it posted as a Service Health item in the 365 Admin Center was rejected when I requested.

    Thanks

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  4. Anonymous
    2016-11-04T18:17:06+00:00

    My CEO got this error for the first time today.

    Looking forward to updates on the holistic fix.

    Outlook 2016 for Mac 15.27

    Cheers,

    Ernesto

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