Outlook Web Add-In Presents Domain Trust Dialog to Users in On-Exchange premises 2019 OWA

[avisheknand]

We have an Outlook web add-in that implements the OnSend event deployed via Admin center centralized deployment that is presenting users with the following prompt:

Your Environment

• Platform [PC desktop, Mac, iOS, Office on the web]: OWA
• Host [Excel, Word, PowerPoint, etc.]: Outlook
• Office version number: Exchange on premises 2019 OWA
• Operating System: Windows 10 (21H2)
• Browser (if using Office on the web): Edge

Expected behavior

I'm expecting to be able to, as the tenant/global admin, to be able to trust the add-in (Similar to how global admins grant consent to apps to avoid users faced with consent prompts) such that users aren't presented with the prompt. Is this possible?

Also able to make the OnSend Addin work without the any issue

Current behavior

Instead of experiencing the anticipated functionality outlined earlier, users encounter prompts as described in the summary above. These prompts create an impression that the add-in may not be secure, despite having undergone thorough vetting by administrators.

Steps to reproduce

1.The prompt appears when after hitting send on a message.

Link to live example(s)

1. Unfortunately, I'm not able to provide a live example publicly.

Context

My customer is trying to enforce compliance on messages as they are being sent, so it's imperative that we're able to leverage an OnSend event add-in.

[avisheknand]

Hello any help or guide on this would be appreciated

[exextoc]

The behavior is by design.

Please find the doc around it here : Description of the security update for Microsoft Exchange Server 2019, 2016, and 2013: October 13, 2020 - Microsoft Support

[ajays-msft]

Similar issue #3310 which is closed as by design.

[avisheknand]

Thanks @exextoc and @ajays-msft , we have informed the customer and they are able to use the addin now by adding the domain to the browsers cookie