If you've switched to new Outlook and noticed something's missing, you're not imagining it — several classic Outlook features are still unavailable or only partially functional in the new version.
Here's the current rundown, with a workaround for each.
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Offline access
New Outlook now supports substantial offline functionality, including synced mail, calendar, contacts, settings, and attachments. However, Microsoft currently lists offline support as only partially available compared to classic Outlook. New Outlook's offline mail sync is limited to a defined window, currently up to 180 days, whereas classic Outlook can cache the entire mailbox.
Workaround: Enable the limited offline mode under Settings → General → Offline. If you regularly need extensive offline access for the full mailbox, classic Outlook or an alternative desktop client may be a better fit.
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PST file support
New Outlook now supports PST files, including opening and importing them, but its PST functionality remains more limited than classic Outlook. In addition, opening an existing PST requires classic Outlook to be installed alongside new Outlook, with the same 32-bit or 64-bit architecture, and a Microsoft 365 subscription.
Workaround: Keep classic Outlook available for workflows that depend heavily on local PST archives, or use another client that supports the required PST workflow.
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Advanced rules and Quick Steps
In new Outlook, Rules and Quick Steps do not yet have full feature parity with classic Outlook. Quick Steps are available for common one-click actions such as moving, flagging, or forwarding messages, but some of the more advanced options available in classic Outlook are missing. Rules also cannot currently be imported or exported, which can make it harder to migrate an existing rules setup from classic Outlook.
Workaround: Recreate the required rules and Quick Steps in new Outlook, or keep classic Outlook for workflows that depend on functionality that hasn't carried over.
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COM add-ins and VBA macros
Third-party add-ins built for classic Outlook's COM or VSTO framework don't work in new Outlook for Windows. Microsoft lists COM/VSTO add-ins, VBA, and macros as unsupported in new Outlook.
Workaround: Check whether your add-in vendor offers a web add-in compatible with new Outlook. For COM add-ins that aren't supported in new Outlook, or for workflows that depend on VBA or macros, you'll need to continue using classic Outlook.
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Shared mailbox delegation
New Outlook supports shared mailboxes, but not all delegate and shared-mailbox scenarios are supported to the same extent as in classic Outlook. Features involving access to another user's mailbox or calendar, delegate permissions, and sending on another user's behalf can still have limitations.
Workaround: Before switching, test the specific delegation tasks your organization relies on — such as accessing another user's calendar, managing their mailbox, or sending messages on their behalf. Use classic Outlook where the required delegation feature is not yet supported.
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Deep UI customization
Classic Outlook offers deeper customization and legacy integration capabilities that aren't available in new Outlook. Custom forms and the Outlook Object Model, for example, remain unsupported.
Workaround: There isn't currently a workaround inside new Outlook itself for some of these legacy capabilities — it's a genuine trade-off of the redesign.
Or avoid the problem entirely
Instead of waiting on Microsoft's rollout schedule or bouncing between classic and new Outlook depending on which feature you need that day, eM Client offers a desktop alternative with full offline access, powerful rules, Quick Actions, Snooze, Watch for Replies, advanced search, attachment search, encryption, and integrated email, calendar, tasks, contacts, notes, and chat.
eM Client 11 takes the alternative further with an AI Assistant, AI writing and summaries, natural-language search, AI-generated rules, Quick Replies, and built-in MCP support, allowing AI assistants to connect to the mailbox and perform actions.
FAQ
Why did Microsoft remove features in new Outlook?
It's a ground-up rebuild rather than a direct port, so some legacy functionality is still being reimplemented while other legacy capabilities aren't supported in the new architecture.
Is there a timeline for full feature parity?
Microsoft hasn't committed to a fixed date publicly. Its official feature comparison is the best source for the current status and upcoming changes.
Is there a client that already has these features today?
Yes — eM Client provides a mature desktop alternative to new Outlook, with a broad set of productivity and customization features. Its upcoming version 11 also adds substantial AI capabilities, giving users another option if they want more advanced email automation.
Stop waiting on Microsoft