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Support for Windows Mail, Calendar and People ended on December 31, 2024. Microsoft’s supported replacement is the new Outlook for Windows, but you can also choose another maintained email client or your provider’s webmail. Before switching, determine which messages and contacts are stored locally and which are already synchronized with your account.
Three options to compare
| Option | Useful for | Check before switching |
|---|---|---|
| New Outlook for Windows | Microsoft’s supported Mail replacement and integrated calendar | Account support, available offline features, cloud-sync permissions and any subscription features |
| Mozilla Thunderbird | A maintained desktop client with multiple accounts and extensions | Provider authentication, add-on compatibility and import requirements |
| Provider webmail | Browser access without installing a desktop client | Offline needs, browser access and how local-only data will be imported |
Start with Microsoft’s Outlook for Windows page or Thunderbird’s official site. New Outlook is different from classic Outlook; do not assume their features, licensing or import workflows are identical.
Protect messages and contacts first
- Sign in to the provider’s webmail and compare its messages, folders and contacts with what you see locally.
- Identify any local-only emails, calendar entries or contacts and export them using Microsoft’s supported instructions before removing the old application or profile.
- Store exported files somewhere you can back up. Confirm their format is supported by the destination application.
- Add the account to the new client using its supported sign-in method, then verify send, receive, folders, contacts and calendar behavior.
- Keep the old exports until you have checked the migration and your backup.
Choose by account and workflow
IMAP normally synchronizes mail folders, while a legacy POP setup may have downloaded messages that no longer exist on the server. Provider sign-in rules can require OAuth or an app-specific password. Check the provider and new client’s current instructions rather than disabling account security to make an old login work.
If offline reading, local archives or PST files are essential, check the current client’s supported workflow and test it with a copy. Feature availability changes, so a blanket claim that one app supports every archive or account is unreliable.
Why Nylas Mail is not on this shortlist
The old Nylas Mail repository is archived. An archived open-source client should not be promoted as a maintained everyday replacement without checking its security and provider compatibility. Open source by itself does not establish continuing maintenance.
Check the operating system too
Installing a new mail client does not extend support for an old Windows release. Our operating-system update guide explains how to check the supported update path. Complete the mail migration separately so an OS change does not erase the only copy of local data.