"Add-in X is blocking the send of this message"

[krzysztof-plutoflume]

Provide required information needed to triage your issue

Several users of our Smart Alerts add-in report that they experience the following error message from Outlook when they try to send an email: "Add-in X is blocking the send of this message". The error pop-up does not have an option to send the email anyway, even though our add-in uses the "soft block" send mode. The user is able to send the email upon retrying — see the screen recording below.

0223.mov

What circumstances trigger this type of error message? It this expected behaviour on Mac?

Your Environment

• Platform [PC desktop, Mac, iOS, Office on the web]: Mac
• Host [Excel, Word, PowerPoint, etc.]: Outlook (New UI)
• Office version number: 16.106.1 (26021521)
• Operating System: macOS
• Browser (if using Office on the web): N/A

Expected behavior

Add-in completes processing successfully or Outlook presents one of the documented error messages.

Current behavior

Outlook displays the message: "Add-in X is blocking the send of this message".

Steps to reproduce

1. Click Send to activate the OnMessageSend add-in.

An affected user provided a screen recording of the issue, see above. I'm not able to reproduce the issue on my side.

Context

This results in poor user experience for our users.

[JuaneloJuanelo]

@krzysztof-plutoflume the softBlock mode does NOT provide a "Send Anyway" option. for that you want to use the "PromptUser" mode. that been said that message is shown by your add-in blocking the send. the user should not be able to send the email after sending . This is something we are investigating with Incident 752906728.

[neprasad-microsoft]

Hi @krzysztof-plutoflume
We tried to repro this issue on our side but were not able to repro. Can you help with a few things which might help us root cause -

• Has this started happening recently? Do you know when it was last working correctly?
• If possibe please share your add-in. You can share it in a GitHub repo and give us access and delete it once it is downloaded.
• Can you share the diagnostic id generated by following the steps here for Mac - https://github.com/OfficeDev/office-js/wiki/Collecting-log-files-for-Outlook-Add%E2%80%90ins-issues .

[krzysztof-plutoflume]

@neprasad-microsoft Thanks for looking into it.

I've checked and it looks like this message is shown by Outlook when the add-in specifies SmartAlertsEventCompletedOptions with allowEvent: false and errorMessage which is either unset or an empty string. However, I'm struggling to see how our add-in would produce this result. Do you know about any other cases where Outlook would show the message "Add-in X is blocking the send of this message"?

Unfortunately the issue was reported by a user and I can't reproduce the issue myself or provide more details at this time, but your insight on the above would be helpful.

[neprasad-microsoft]

In case of softBlock, if you send allowEvent:false, then we show this message. If you are not seeing this, then it should be debugged. But the issue is that why is it not getting blocked the second time also. If your add-in passing allowEvent:false, then the error popup is the correct behavior.
It is difficult to debug this without the Diagnostic ID or add-in's manifest. So if possible please share these.
Do you have any other LaunchEvent in your manifest and do you pass allowEvent:true in those event's event.completed. If you are doing that, then it might cause undefined behavior.