Questions about add-in behavior of shared mailboxes about office-js

[neprasad-microsoft]

Add-ins will continue to work in shared mailboxes in Outlook web when opened in the same tab. However, for the scenario where users can “Open another mailbox” in a new tab, users may run into some of the issues outlined above. We are actively working on resolving this issue for the new tab scenario in the upcoming planning cycles. We appreciate your understanding and apologise for the inconvenience caused.

[neprasad-microsoft]

This is an unsupported scenario at this time. While shared mailboxes allow multiple users to access a common mailbox, our team does not provide official support for add-ins in shared mailboxes when opened in a new tab. As a temporary workaround, please re-deploy the add-in to the end user's mailbox and the shared mailbox, in case your add-in disappears from the Shared Mailbox.

[mailchecktool-admin]

#3769 (comment)
From this reply, I was under the impression that the add-in supports opening a shared mailbox in a new window from “Open Other Mailbox”, but is it correct that the add-in does not work in this scenario?

[neprasad-microsoft]

We understand that the feature support was available earlier, however due to technical challenges and an increased focus on security, we no longer support add-ins in shared mailbox on Outlook web. Please refer to the workarounds proposed above. We expect to have an ETA to address this issue in the coming months. Appreciate your patience on this!

[mailchecktool-admin]

Is it correct that “no longer supported” means that the add-in will no longer work (or be available) in shared mailboxes in the future?
Or does it mean that the current unstable state will continue?

If you know when support will end at this time, please let us know.

[mailchecktool-admin]

Am I correct in understanding that the resolution of this issue will take place within the next few months and no date has been set?
"We expect to have an ETA to address this issue in the coming months.” but where is this going to be shared?

[cody-lettau]

This is a pretty significant deprecation in functionality for shared mailboxes and add-ins. We have many customers who use shared mailboxes and open them in a new tab that expect our add-in to function as it has previously.

This needs to be prioritized. When can we expect this to be fixed and back in a working state? Having an update on ETA in months is not sufficient...

[akshayta23]

Please refer to our updated documentation that outlines how add-ins will work in shared mailboxes on Outlook web when opened in a new tab - https://learn.microsoft.com/en-us/office/dev/add-ins/outlook/delegate-access?tabs=web%2Cjsonmanifest#supported-setups .

We have also suggested a few workarounds to help reduce the impact to your organization and end users. At this time, due to our org's priorities, we cannot commit to a specific ETA. But rest assured that we are trying to address this issue soon, as we understand that this is a critical functionality for our users. Appreciate your understanding here.

[cody-lettau]

@akshayta23 if this is not being considered a bug and was planned removal of critical functionality (completely removing support for add-ins in shared mailboxes on one of your platforms), why was this not announced? This is a major pain point for our customers and not being able to communicate this is pretty poor customer service.

Communication of changes like this needs to improve going forward.

[jgibbs2680]

I was able to add the shared mailbox to Outlook mobile which allowed me to send an email.