Apple Mail vs Thunderbird on a Mac

Pick Apple Mail if you use a Mac with an iPhone or iPad and want the free app that's already there, with junk tools and Apple Intelligence built in. Pick Thunderbird if you also use Windows or Linux, want mail, calendars and contacts in one open-source app, or want no AI in your mail at all.

Both are free, so the choice comes down to where you work and what you want the app to do for you. The facts below come from Apple's Mail guide for macOS 27 and from Thunderbird's own pages, as of November 2026.

Apple Mail and Thunderbird at a glance

Alrighty is our app. It's in the first column as a third option, with its own short section after the comparison.

	Alrighty	Apple Mail	Thunderbird
Runs on	Mac (Apple silicon), Windows, Linux	Mac, with Mail on iPhone and iPad	Mac (macOS 10.15 or later), Windows, Linux, Android
Accounts	iCloud, Gmail, Outlook	iCloud, Gmail, Exchange, school, work, other	Providers not named on its pages
Price	14-day trial, then Free plan or Pro	Comes with macOS	"Free forever," funded by donations
Where mail is kept	Your computer, searched on your computer	Your Mac and your provider	"Stored and processed locally on your device"
Unwanted mail	Stop mail, Clean up, Filters	Junk filter, Unsubscribe, block up to 3,000 senders, categories	Filters you set up
AI, and its default	Reply drafts start when you open a reply, signed in; your own AI is off until you connect it	Apple Intelligence summaries show by default where available	None

Is Thunderbird better than Apple Mail?

It depends on what you need beyond the Mac. Thunderbird is the better choice if you switch between a Mac and a Windows or Linux computer, because the same app runs on all three (Thunderbird). Apple Mail is the better choice if your other devices are an iPhone and an iPad, because Mail is there too and works with Apple's privacy and AI features.

Thunderbird also keeps "messages, calendars, and contacts in one fast app." Apple puts calendars and contacts in separate apps. Thunderbird is open source. Apple Mail is not.

Does Thunderbird run well on Apple silicon Macs?

Yes. Thunderbird's system requirements list "Macintosh computer with an Intel x86 or Apple Silicon processor" and "macOS 10.15 or later." That's a much older floor than most Mac mail apps, so Thunderbird is an option on a Mac that can't run the current macOS. Version 159.0 was released on October 27, 2026 (release notes).

Apple Mail updates with macOS, so a new Mail comes with each new version of the system.

Which is better at stopping junk mail?

Apple Mail does more out of the box. Its guide to reducing junk mail describes three tools:

• A junk filter that learns. Each time you mark a message as junk or not junk, "the junk mail filter improves."
• Unsubscribe. On a mailing-list message, click Unsubscribe in the banner, then OK.
• Block Sender. "You can block up to 3,000 senders," and blocked mail can go straight to the Trash.

Mail also sorts your inbox into Primary, Transactions, Updates and Promotions, though categories are "not available in all countries or regions" (Apple).

Thunderbird's home page promises you can "Filter and organize the way you like," and filters are its strength. Mozilla's help pages for its junk settings would not load for this check, so this page makes no claim about Thunderbird's junk filter or unsubscribe tools.

Does Apple Mail or Thunderbird have AI?

Apple Mail has Apple Intelligence. Thunderbird has none, on purpose.

In Apple Mail on macOS 27, "a short summary automatically appears under each unread email in your inbox," and Apple Intelligence "can suggest replies to emails you receive" (Apple). To turn summaries off, choose Mail > Settings > Viewing, then deselect Summarize Message Previews. Apple Intelligence "is not available in all languages or regions," so what you see depends on where you live and your Mac's language.

Thunderbird's home page says it doesn't "secretly train AI with your private conversations," and it advertises no AI features. If you want a mail app with no AI to switch off, Thunderbird is it. Our list of email apps without AI has more.

Which is more private, Apple Mail or Thunderbird?

Both keep your mail on your Mac. They protect different things.

Thunderbird's privacy notice says your messages and address book "are stored and processed locally on your device and never sent to us." Two things do go to Mozilla. When you add an account, "your email domain may be sent to Mozilla's configuration database" to find the right settings. And Thunderbird "sends telemetry about your interactions with Thunderbird to us," which you can turn off.

Apple Mail's strength is hiding you from senders. With Protect Mail Activity on, "your IP address is hidden from senders and remote content is privately downloaded in the background" (Apple). Thunderbird's privacy notice doesn't cover remote images in messages.

Which has better search?

Apple says Mail "can provide search results based on what you mean, not just the words you type," and supports filters like from: with AND, OR and NOT (Apple). Many Mac users still find it misses mail they can see; our guide to Apple Mail search not working covers why and how to fix it. Mozilla's search help page would not load for this check, so this page makes no claim about Thunderbird's search.

Which works with more email accounts?

Apple's guide says you can add "iCloud, Gmail (Google), Exchange, school, work, or other" accounts (Apple). Thunderbird's home page doesn't name providers. Its privacy notice says sign-in credentials "are exchanged for OAuth tokens," and it looks up each account's settings in Mozilla's database. Thunderbird lets you "manage all accounts separately or in a unified inbox."

Where Alrighty fits

Alrighty is a third app for people with iCloud, Gmail and Outlook accounts whose two complaints are junk and search. Like both apps above, it keeps your mail and its search index on your computer.

• Stop mail. One action unsubscribes every way a message offers, archives the sender's mail, and moves their new mail out as it arrives. Apple Mail's Unsubscribe and Block Sender are two steps; Stop mail is one.
• Clean up lists likely scams, cold outreach and newsletters you never open, so you can stop them all at once.
• Search that matches meaning, on your computer, across every account: "when is my flight" finds the airline's confirmation.
• Your own AI. Claude, ChatGPT's desktop app, Codex or a local model can read your mail once you turn it on with Connect AI. It works in a window you watch, and nothing sends until you click Send.

What it doesn't do. Alrighty runs on Mac, Windows and Linux, but has no iPhone or Android app. It takes iCloud, Gmail and Outlook only, with no Yahoo or other IMAP accounts, and has no calendar. It isn't free in the way these two are: a 14-day trial with no card, then a Free plan or Pro. Signed in, its suggested replies and Clean up send the emails they read through Alrighty's server to AI model companies, OpenAI among them, so it's not the pick if you want no AI. It's also a new app.

Which should you pick

• iCloud, Gmail and Outlook on a Mac, with junk stopped in one step and search that finds it: Alrighty.
• A Mac plus an iPhone or iPad, free and built in: Apple Mail.
• Mac plus Windows or Linux in a free, open-source app, with Android too: Thunderbird.
• Mail, calendar and contacts in one open-source app: Thunderbird.
• No AI in your mail at all: Thunderbird.
• An older Mac that can't run the latest macOS: Thunderbird, which needs macOS 10.15 or later.

For other options, see Apple Mail alternatives and Thunderbird alternatives. Our pick of free email apps for Mac goes further. More pairs are on our compare page.

Questions

Can I use Thunderbird and Apple Mail at the same time?

Yes. Both read your mail from your provider's servers, so you can add the same accounts to each and compare them for a week. Junk training and filters you set up in one app don't carry over to the other, so set them up in the one you keep.

Does Thunderbird work on iPhone?

Thunderbird's home page offers Thunderbird Mobile for Android through Google Play and F-Droid. It names no iPhone app. On an iPhone, Apple's Mail app is the one that matches your Mac.

Is Thunderbird really free?

Yes. Thunderbird's home page says "Free forever" and that it's "funded by user donations." The page also links to a separate service called Thundermail, but describes nothing about it, and the app works with the accounts you already have.

Do Apple Mail summaries send my email to Apple?

Apple's Mail guide doesn't say where summaries are processed. They work only where Apple Intelligence is available, and you can turn them off in Mail > Settings > Viewing.