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
    2016-12-16T18:40:50+00:00

    That was one of the suggested troubleshooting fixes suggested by MS for us, but didn't work. Problem just returned again a few days later. Still waiting on a fix...

    k.

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  2. Anonymous
    2017-02-06T20:15:46+00:00

    Alright folks - I think we were finally able to identify the race condition that was causing this mess.  As of build 15.01.0917.000, you should no longer be hitting this issue.  Note that in an EWS response, the SOAP header indicates what build you are on.  Sorry this one took so long.

    The basic issue was that even though you were doing a "new" operation, there are these various processors on the server side that were touching the item, and one or more of them were touching and saving the item as part of their processing.  As such, the item "looked" different and the store would complain that the change key was stale.  The fix was to ensure that no "saves within saves" occurred.

    Just to reiterate, there is nothing wrong with your client or client cache - this was a server side only condition and the only workaround was to send the item from the draft folder (which is obviously not an acceptable solution).

    Also note that this is not specific to EWS - it will also affect the REST API and really any protocol that Exchange offers.

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  3. Anonymous
    2017-02-06T20:21:19+00:00

    So as of right now would you say the issue is resolved? Or do we need to wait for an update server side and if so when is that planned.

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  4. Anonymous
    2017-02-06T20:29:36+00:00

    The issue is resolved as of build 917.  However, you have to wait for that build to roll out in production.  I would assume a few weeks for WW saturation.  Note however that you should start seeing relief before that depending of course on where your mailboxes are hosted.

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