Using New Outlook on Windows for professional communication and productivity
Hi @Gary
You can refer to the AI's response. Based on my further research in Microsoft documentation, this behavior is by design.
As I understand it, Outlook add-ins can be configured to support pinning (for example, by using SupportsPinning in the add-in manifest). However, there is currently no supported method to have the task pane pinned by default through either the manifest or JavaScript/Office.js. The pinned state is controlled by the end user, who must manually select the Pin option in Outlook.
Reference: Implement a pinnable task pane in an Outlook add-in - Office Add-ins | Microsoft Learn
As a result, the scenario of automatically pinning the task pane when the add-in loads is not currently supported by the Outlook add-in platform.
If this functionality is important for your organization, I would recommend submitting feedback through the Feedback Portal. This dedicated platform allows users to highlight how specific product limitations impact their workflows and suggest improvements that would provide meaningful value to their business.
Your feedback may also help other customers facing similar challenges and can increase visibility of the request within the product team. If you decide to submit feedback, please feel free to share the feedback link here. I'd be happy to review it and upvote it to help increase its visibility.
I hope this helps address your concerns.