How to download and install Thunderbird on Mac

Before you download

Thunderbird has one installer that runs natively on Apple Silicon and Intel Macs, so there is no version to choose. Each language has its own file: the link on this page downloads the English version, and Thunderbird’s website offers the others.

Thunderbird needs macOS 10.15 Catalina or later. Download it only from thunderbird.net or mozilla.org.

How to install Thunderbird

1. Open the downloaded Thunderbird .dmg in your Downloads folder.
2. In the window that opens, drag Thunderbird to the Applications folder.

3. Eject the Thunderbird disk: click the eject button next to it in the Finder sidebar.
4. Open Thunderbird from Applications and click Open when macOS asks about an app downloaded from the internet.

Add your mail account

1. On first launch Thunderbird opens account setup.
2. Enter your name, email address and password, then click Continue.
3. Thunderbird looks up the server settings. Keep IMAP so your mail stays on the server, and click Done.
4. For Gmail or Outlook.com, your provider’s sign-in window opens instead: sign in there and allow access.

For iCloud Mail, use an app-specific password created in your Apple Account, not your main password.

What to set up after the first launch

• Mail from Apple Mail or Outlook. If your mail is on a server, as with Gmail, iCloud, Outlook.com or any IMAP account, adding the same account in Thunderbird brings all of it over. Messages kept only on your Mac, under On My Mac in Apple Mail, aren’t on a server: drag them into a folder of your mail account in Apple Mail first.
• Contacts, calendars and old Thunderbird profiles. Tools › Import brings them in from files or from another Thunderbird installation.
• Default mail app. Thunderbird offers it on first launch. Later: open Apple Mail’s settings and choose Thunderbird as the default email reader on the General tab.
• Disk space. Thunderbird keeps a copy of your mail on the Mac, so its folder grows with your mailbox.
• The installer. Move the Thunderbird .dmg from Downloads to the Trash once Thunderbird runs.

If Thunderbird won’t install or open

• «Thunderbird is damaged and can’t be opened». The download was incomplete. Delete it and download it again from Thunderbird’s website.
• Thunderbird doesn’t start on an older Mac. Check your macOS version in About This Mac: it needs macOS 10.15 or later.
• The account won’t connect. Check the password. For iCloud, use an app-specific password, and for a work account ask your administrator for the server settings.
• Nothing helps. Remove Thunderbird completely and install it again: see how to uninstall Thunderbird on Mac.

Alternatives to Thunderbird

• Microsoft OutlookMail and calendar, free with personal accounts.
• SparkA smart inbox and shared drafts.