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Absence of basic Outlook functionality

ThomasNzN 0 Reputation points
2026-04-13T09:24:46.0966667+00:00

Hello, how many more years to wait for Outlook on-premises support for UWP Outlook (new) app and new Outlook for Mac app? Every time, for over a year, I look and see "Coming Soon". Is it, really?

I work in a company and we use Office 365 actively, 250+ users, but we don't use Microsoft's Outlook services as we have our own Exchange mailbox locally and manage it by ourselves. The legacy Outlook 365 app requires a bunch of registry fixes to stop spamming login prompts and stop trying to sync with Microsoft's Outlook mailbox which doesn't even exist, and none of "new" Outlook apps work. Before UWP Outlook (new) there was UWP "Mail & Calendar" app for Windows and our employees were very happy with it, it simply WORKED.

Recently we had an issue where Mac Outlook users can't receive shared calendar invitations because Legacy Outlook for Mac does not understand invitations and instead of "Accept" it sends "sharing_metadata.xml" file. If doing it manually, you can't access a shared Calendar if it's a secondary calendar, the app can only access users primary Calendar, there is no option or menu to chose which calendar you want to view, you can only select user from the list to view their primary calendar. Solution - use new Outlook which does not support "Exchange". Most Mac users in our company prefer using OWA variant rather than the app.

Not to mention, Microsoft is trying desperately to force people to use their new UWP "Outlook" app on Windows by installing it with every major Windows update. Less experienced users always write in tickets that their "Outlook" is not working anymore, not realizing they have 2 versions of outlook and for some weird reason the "not compatible one" bumps itself up in the start menu to the top. We constantly need to run scripts or manually remove it.

What progress is made towards Outlook app Exchange support for both Mac and Windows? It's been 2 years, if not more. Will we have people on Mars sooner than on-premises support in modern Outlook apps?

Outlook | MacOS | Legacy Outlook for Mac | For business
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  1. Michelle-N 15,545 Reputation points Microsoft External Staff Moderator
    2026-04-13T10:33:00.2766667+00:00

    Hi @ThomasNzN

    Based on the information you provided, I understand that you are managing a 250+ user environment with a local Exchange setup and are incredibly frustrated by the lack of native on-premises support in the New Outlook apps for both Windows and Mac. You are constantly dealing with forced installations of an incompatible Windows app, broken shared calendars in Legacy Outlook for Mac, and the need for numerous registry workarounds just to keep your users functional.

    I completely understand how exhausting it is to battle forced OS updates and explain to end-users why their email clients suddenly stopped working. It is incredibly frustrating to wait years for basic functionality while having to constantly patch the legacy apps.

    To give you a candid update based on the current situation: at this time, there is no official timeline for full, native on-premises support (MAPI/EWS) in the New Outlook for Windows app. While previous roadmaps hinted that support might be tied to Exchange Server Subscription Edition CU1 (which was targeted for late 2025), it has still not materialized in a way that is practically usable for the vast majority of standalone on-premises systems.

    For now, the Outlook Classic (full desktop) application remains officially supported for on-premises and hybrid environments, so you do have a supported platform, even though it currently requires your manual registry interventions to stop the Microsoft 365 login prompts.

    I know this is a highly disruptive waiting game and not the answer you were hoping for. To help push this issue up the priority list, I strongly encourage you to submit your feedback directly to the product engineers by going to Help > Feedback within the Outlook app.

    Please note that this is a user-to-user support forum. Moderators and contributors, including external Microsoft employees, cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas.

    Thank you for understanding.

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.  

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  2. Q&A Assist
    2026-04-13T09:25:07.0333333+00:00
    AI generated content. This question contains an answer created with AI from Q&A Assist. Learn more

    For Outlook for Mac, Exchange on-premises support in the new Outlook is still listed as “Upcoming” and not yet generally available. The current guidance is:

    • Legacy Outlook for Mac continues to work with Exchange On-Premises mailboxes and will keep working there even after October 2026; only connectivity to Exchange Online will stop at that time.
    • The new Outlook for Mac already supports multiple account types (Exchange Online, Outlook.com, Microsoft 365, Google, iCloud, IMAP, POP, etc.), and Exchange (on-premises) is explicitly marked as “Available” in the Outlook for Mac features list for version 16.58+.
    • Microsoft has stated that Outlook for Mac will continue to respect admin preferences for staying on legacy Outlook where needed, and customers blocked from accessing certain features are advised to contact support for assistance.

    For Windows “new Outlook” (UWP-style app), the provided context does not include any committed timeline or status update for full Exchange on-premises support. The only relevant information in the context is that new Outlook is not MAPI-compliant and therefore cannot yet replace classic Outlook for scenarios that depend on MAPI integration (for example, mail merge from Word or “Send as attachment” from Office apps). In these cases, classic Outlook must still be used.

    From the available information:

    • Legacy Outlook for Mac remains the supported option for Exchange on-premises and will continue to work with on-premises mailboxes beyond October 2026.
    • New Outlook for Mac has Exchange (on-premises) listed as available in the feature matrix for supported account types (version 16.58+), but Exchange Online-only deprecation of legacy Outlook in October 2026 means on-premises customers can stay on legacy if needed.
    • No specific roadmap dates or guarantees are provided in the context for when the Windows new Outlook/UWP app will fully support Exchange on-premises or MAPI-dependent workflows.

    For concrete, tenant-specific status and timelines, the recommended actions are:

    1. Monitor the Microsoft 365 Roadmap for Outlook for Mac and Outlook for Windows for updates on Exchange on-premises support and feature parity.
    2. Keep legacy Outlook for Mac and classic Outlook for Windows in place for Exchange on-premises users and MAPI-dependent workflows until official support for those scenarios is documented for the new Outlook clients.
    3. If users are blocked by missing features in new Outlook for Mac, open a support case as advised so Microsoft can provide current guidance or mitigations.

    References:

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