New Outlook for Windows gets .pst support & Copilot upgrades with June 2025 update

Microsoft isn’t backing down from the new Outlook for Windows, no matter how much users miss the old version. Despite continued criticism, the company is still rolling out steady improvements based on feedback. The June 2025 update just dropped, and it’s one of the most feature-packed updates in a very long time.

June 2025 update brings better .pst support and more to the new Outlook for Windows

If you’re still hanging onto old .pst files, the June update for new Outlook is for you. You can now reply to and forward emails stored in them—a top request. More improvements for .pst handling are already in the works.

For Copilot users, the update makes sharing smarter. If you have Copilot Pro or AI credits through a Microsoft 365 Personal or Family subscription, you can now use Copilot even on personal accounts from Gmail, Yahoo, iCloud, and others, not just your main Microsoft account.

There’s also a new AI-powered writing assistant. Before sending an email, Copilot can now offer tone and clarity suggestions and help you gauge how it might come across. Don’t like the help? You can now turn off Copilot entirely in Settings under the new Copilot control page.

Offline support hasn’t been forgotten either in the June update for new Outlook for Windows. Microsoft increased the default mail sync window from 7 to 30 days. You can also now cancel a sent email and access search folders without an internet connection.

Other additions include:

• Easily move emails between personal accounts (disabled by default in enterprise)
• Add shared folders to your Favorites
• “External” tags in contact suggestions so you don’t accidentally email outside your org

Microsoft says all of these changes are part of making the new Outlook more flexible and user-friendly. Whether that’s enough to win over classic Outlook fans, though—that’s still up in the air.