New Outlook vs Old Outlook: What’s Changed And Which Should You Use?

What Is the "New Outlook" vs "Old Outlook"?

New Outlook is a completely rebuilt email client that launched in August 2024. Microsoft designed it to look and function identically whether you're on Windows, Mac, or accessing email through a browser using web-based technologies.

Old Outlook, now officially rebranded as "Outlook Classic," refers to the traditional desktop application that's been part of Microsoft Office since 1997 and is included with Office 2016, Office 2019, and Microsoft 365 subscriptions. If you're wondering, "What is Legacy Outlook?", then it's simply another name for the same Classic version, which Microsoft has committed to supporting until at least 2029.

The easiest way to tell which version you have is to look for the toggle switch in the upper-right corner of your Outlook window. If you see "Try the new Outlook" there, you're running Classic Outlook with the option to test the new version. Already switched? The new Outlook displays a cleaner, more minimalist interface and lacks the traditional File menu entirely.

Another quick check that you can do is to open your Start menu and look at how Outlook appears. Classic Outlook shows up simply as "Outlook" or "Outlook (classic)" while the new version may display a "New" badge next to its icon.

You can also tell by the ribbon. Classic Outlook features the familiar toolbar packed with buttons and options, while the new version uses a streamlined command bar with fewer visible controls. For a deeper look at what to expect from the redesigned interface, our honest New Outlook for Windows review covers the real-world experience.

New Outlook: Modern Features at a Glance

So what does the New Outlook actually bring to the table? Microsoft rebuilt the application from the ground up, and there are several major improvements that make it worth taking a closer look at.

A cleaner, more consistent interface

The New Outlook interface moves away from the dense, button-heavy ribbon that defined Classic Outlook for decades. Instead, you'll find a simplified toolbar with core commands and plenty of white space for good readability. The layout mirrors what you see in Outlook on the web to create a consistent experience across all your devices.

Navigation feels more intuitive too. Mail, Calendar, People, and Tasks all live in a left sidebar to make jumping between functions easier. You can also customize folder colors in the new version, which is something Classic Outlook never offered.

Faster performance

Because New Outlook processes most data in the cloud rather than locally, startup times have improved significantly. You won't wait for a massive OST file to load or watch the app crawl due to years of cached emails.

The only downside to the cloud-based nature of New Outlook is that you need a reliable internet connection to use the mail client as intended. The app caches recent messages for offline access, but it won't store your entire mailbox history locally like Classic Outlook does.

Deep Microsoft 365 integration

Microsoft built New Outlook to serve as a productivity hub with a built-in Teams integration that lets you schedule meetings, see presence indicators, and start chats without switching applications. There are also OneDrive and SharePoint connections, which make attaching cloud files painless.

The app even syncs tasks with Microsoft To Do and pulls in your calendar events from across Microsoft 365. If you're already invested in the Microsoft ecosystem, the productivity integrations can really save you a lot of time.

Copilot AI capabilities

With a Copilot license, you can use AI to draft emails, summarize long conversation threads, get coaching on your writing tone, and more. To understand what Copilot brings to your daily workflow, check out our breakdown of what Copilot is used for in Windows and Office.

Microsoft has made it clear that Copilot development will focus on the new platform going forward, so you can expect Copilot in New Outlook to get better and better over time. Sure, you can always use ChatGPT or another AI in your browser, but having it right there in your mail client is really handy.

Enhanced security by default

New Outlook ships with support for the modern OAuth 2.0 authentication standard, cloud-based threat intelligence, which updates continuously rather than waiting for software patches, and built-in phishing defenses that flag suspicious senders and scan links before you click them.

The app also blocks certain legacy features that posed security risks in Classic Outlook, including COM add-ins and VBA macros. While this improves safety, it does create compatibility issues we'll address shortly.

Old Outlook: Familiar and Feature-Rich

Classic Outlook still has a massive user base for several good reasons that all users who are deciding between Legacy Outlook and New Outlook should know about.

A layout you already know

Classic Outlook's interface hasn't changed dramatically in years, and that's actually a strength. The ribbon toolbar puts every feature within reach, and many users have muscle memory built over a decade of daily use that allows them to do what they need to do in Classic Outlook very quickly.

As our guide on how to customize Outlook and personalize your inbox shows, New Outlook does offer some interface customization options, but they are seriously limited compared with Classic Outlook.

Full offline functionality

Classic Outlook downloads your entire mailbox to a local OST file, so you can access years of emails, compose replies, and work through your inbox without any internet connection whatsoever (changes sync automatically once you're back online).

You can also import archives, export mailboxes for backup, and access old emails stored in local data files without restrictions thanks to full read and write support for PST files.

Support for add-ins and macros

The legacy version of Outlook supports COM and VSTO add-ins, so all those specialized tools your organization relies on will actually work. CRM integrations, custom workflow plugins, document management connectors, and industry-specific extensions all require Classic Outlook.

VBA macros also remain exclusive to the classic version. If you've built automation scripts to handle repetitive tasks or your company uses custom forms, New Outlook simply cannot run them. Microsoft has indicated these legacy technologies won't be coming to the new platform.

Multiple profile support

If you need to keep work and personal email completely separate, then Classic Outlook lets you create distinct profiles, each with its own set of accounts, settings, and data files. You can switch between profiles or run them simultaneously in different windows.

On the other hand, New Outlook combines all accounts into a single interface, which works well for many users but doesn't create strict separation between different email identities.

Choosing Between the Two Outlook Versions

The comparison table above makes the decision fairly straightforward once you know your priorities:

• Choose New Outlook if you want a faster, cleaner interface and rely heavily on Microsoft 365 services like Teams, OneDrive, and especially Copilot AI. The new version works best for users who stay connected to the internet, don't depend on legacy add-ins, and prefer a consistent experience across Windows, Mac, and web browsers.
• Stick with Classic Outlook if your workflow depends on COM add-ins, VBA macros, or full offline access to years of email history. Organizations using CRM integrations, custom workflow tools, or PST archives for compliance should wait until Microsoft closes these feature gaps. The same applies if you need multiple profiles to keep different email identities completely separate.

How to Switch Between New Outlook and Old Outlook

The good news is that Microsoft lets you move freely between both versions with just a few clicks. Below you'll find instructions on how to change Outlook to the new version as well as how to switch back to Classic if needed.

Switching from Classic Outlook to New Outlook

Before you switch to New Outlook, it's best to clean up your inbox using Clean Email. A clean inbox makes for a faster and smoother migration. Once your inbox is clean, you can follow these steps:

1. Open Classic Outlook and look for the "Try the new Outlook" toggle in the upper-right corner of the window.
2. Click the toggle to begin the transition. Outlook will download any necessary components.
3. When prompted, choose whether to Import Settings (recommended) or skip this step.
4. Wait for the new version to load. Your accounts and basic settings will carry over automatically.

Both versions can run side by side during this period, so you can compare them directly before making a final decision.

Switching back to Classic Outlook

Should you change your mind, then you can follow these steps to change Outlook to classic view:

1. In New Outlook, click the Help menu in the top toolbar.
2. Select "Go to Classic Outlook" from the dropdown options.
3. Alternatively, look for the toggle switch (same location as before) and turn it off.
4. Confirm when prompted, and Classic Outlook will reopen.

Conclusion: Use the Version That Works for You

Microsoft isn't forcing anyone to abandon Classic Outlook until 2029, so you have plenty of time to evaluate which version works best for you at the moment. That said, New Outlook represents the future of Microsoft's email platform, so it's smart to familiarize yourself with its interface now.

Whichever version you choose today, keeping your inbox organized makes everything easier. A cluttered mailbox feels overwhelming in any interface, while a clean one lets you focus on what actually matters. Consider setting up Clean Email now so your inbox stays manageable through whatever changes come next. When you do eventually make the switch, you'll transition without years of digital clutter.