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
    2016-10-10T21:37:55+00:00

    Hi John

    In my case (and two other people in the team

    1. some.  Generally replies
    2. nothing unusual as far as we can tell and no obvious shared characteristics
    3. Pop up Alert.  Repeats a couple of times then isn;t an issue anymore
    4. No rules in operation

    thanks

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  2. Anonymous
    2016-10-10T19:18:31+00:00

    Kristin,

    1. Is this happening for all outgoing mail or just some of them?  Are they new messages or replies?
    2. Is there anything unusual about the messages (images, size, attachments, etc.)
    3. Is that error message from an pop-up alert?  If you go to "Window" -> "Sync Errors" do you see one or more of the same error?
    4. Are any rules being run that could be moving messages around?

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  3. Jim G 134K Reputation points MVP
    2016-10-09T16:31:20+00:00

    I was going to suggest contacting Microsoft support about this. It sounds like a network latency issue where either the server or Outlook client communications are not happening in the expected order.

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  4. Anonymous
    2016-10-06T06:29:38+00:00

    Haven't heard anything and Microsoft haven't listed this as an issue for Office 365 for Business. Of note, it turned out my client wasn't running the latest update for Office 2011, however, after running the update the problem persists. I'm going to open a ticket with Office 365 Support.

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