Mac Mail Keeps Crashing or Quitting? How to Fix It

If Mail keeps crashing on your Mac, force quit it (Option-Command-Esc) and restart the Mac, then install the latest macOS update. If it still quits, turn off Mail extensions, rebuild the mailbox you were in, and disable accounts one at a time to find the one causing it. Safe mode tells you whether other software is to blame.

If Mail won't open at all, see Mail not opening on Mac.

Quick fixes at a glance

Force quit Mail and restart your Mac
Update macOS
Turn off Mail extensions
Rebuild the mailbox that crashes Mail
Find the account or message causing the crash
Test in safe mode
Reindex Mail (advanced)
Remove the account and add it back

On iPhone or iPad? Jump to Mail keeps crashing on iPhone.

Why Apple Mail keeps crashing

A crash usually has one of five causes:

A damaged message, or a damaged index of your mailboxes. Mail keeps a database of every message so it can list and search them, and if that gets corrupted Mail can crash at launch or when you open a certain mailbox.
One account that syncs badly, often after a password change or a problem on the provider's side.
A Mail extension (plug-in). When an extension is involved, the crash alert often says so: "Mail quit unexpectedly while using the [name] plug-in."
A bug in macOS itself. On the Apple Community forum, people whose Mail crashed when searching in macOS Sonoma 14.0 reported that the 14.2 update fixed it. Updating is worth doing early.
Other software that loads when you log in and interferes with Mail.

When Mail crashes, macOS shows a "Mail quit unexpectedly" alert with a Reopen button. The details of that alert are the crash report, and sending it to Apple is how Apple learns about the bug.

How to fix Mail crashing on Mac

The order matters. The first steps rule out the app and the system, the middle ones find a bad account or message, and the last ones rebuild Mail's data.

1. Force quit Mail and restart your Mac

If Mail is frozen rather than gone, press Option-Command-Esc, or choose Apple menu > Force Quit. Select Mail and click Force Quit. Then restart the Mac from the Apple menu. If the Mac won't restart, press and hold the power button for up to 10 seconds until it turns off, then press it again to turn it back on.

2. Update macOS

Mail is part of macOS, so Mail fixes arrive with macOS updates. Go to System Settings > General > Software Update and install anything waiting. At the time of writing, the current version is macOS 27.0.1.

3. Turn off Mail extensions

Choose Mail > Settings, then click Extensions. Turn off every extension, quit Mail and open it again. If the crashes stop, turn the extensions back on one at a time until you find the one that brings them back, then remove it or check with its developer for an update. Do this first if the crash alert named a plug-in.

4. Rebuild the mailbox that crashes Mail

If Mail crashes when you open one particular mailbox, rebuild it. Select the mailbox in the sidebar, then choose Mailbox > Rebuild. For IMAP and Exchange accounts, Mail discards the copies on your Mac and downloads the messages again from the server, so the mailbox looks empty for a while. On a large mailbox this can take some time.

5. Find the account or message causing the crash

If Mail crashes as soon as it opens, or every time new mail arrives, one account is often the trigger. Choose Mail > Settings, click Accounts, select an account and deselect "Enable this account". Do one account at a time and use Mail for a while after each change. If the crashes stop when a particular account is off:

Sign in to that account's webmail and move or delete the last few messages that arrived before the crashes began.
Turn the account back on in Mail.

To turn Mail off for an account across the whole Mac, rather than only inside Mail, use System Settings > Internet Accounts.

6. Test in safe mode

Safe mode starts the Mac without login items and extensions that macOS doesn't need, checks the startup disk and clears some system caches.

Mac with Apple silicon: shut down. Press and hold the power button until you see "Loading startup options". Select your startup disk, then press and hold Shift and click "Continue in Safe Mode".
Intel-based Mac: turn on or restart the Mac and immediately press and hold Shift. Let go when the login window appears.

You might see "Safe Boot" in red in the upper-right corner of the login window. Open Mail and use it as normal. If it doesn't crash in safe mode, a login item or other software is the likely cause. Restart normally and remove recently installed apps or login items one at a time.

7. Reindex Mail (advanced)

If Mail ever shows an error with a "Quit and Rebuild Index" button, use that button first. Mail will import your messages again the next time it opens. If you never see that option and Mail still crashes, you can make Mail rebuild its index by hand. This is the closest thing Mail has to clearing its cache.

Back up your Mac with Time Machine.
Quit Mail.
In the Finder, choose Go > Go to Folder, type ~/Library/Mail and press Return.
Open the folder named V followed by a number (V10 on recent macOS versions), then open MailData.
Move every file whose name starts with "Envelope Index" into a new folder on your desktop. Don't delete them.
Open Mail. It rebuilds the index, which can take hours on a large mailbox.

If something goes wrong, quit Mail and put the files back where they were.

8. Remove the account and add it back

Apple's last-resort fix is to remove the account and set it up again. First sign in to your webmail and check that your mail is on the server. Messages kept only in "On My Mac" mailboxes or in a POP account live on your Mac, so back them up first. Then remove the account in Mail > Settings > Accounts and add an account to Apple Mail again.

Mail freezes, glitches or is very slow

A Mail that hangs, beach-balls or takes ages to load messages isn't always broken. Often it's busy.

Check what Mail is doing

Choose Window > Activity, or press Control-Command-0, to see what Mail is downloading, sending or indexing. After a major macOS update, Mail may need to update its mail library, and it can be slow until that finishes. Give it time on power and Wi-Fi before you change anything.

Give Mail less to handle

Choose Mailbox > Erase Deleted Items to empty the Trash, and Mailbox > Erase Junk Mail to clear Junk. Moving years of old mail out of your inbox also helps; see how to archive old messages in Mac Mail.

"Mail interrupted shut down"

The alert says "“Mail” interrupted shut down." It means Mail didn't quit when your Mac asked it to, so the shutdown stopped. Switch to Mail, save or close any message you were writing, quit Mail and shut down again. If Mail has stopped responding, macOS offers to force it to quit and continue the shutdown. If this happens every time, work through the fixes above.

If searching is what makes Mail crash or hang, see Mac Mail search not working. Its reindex steps apply here too.

Mail keeps crashing on iPhone or iPad

The iPhone version of Mail has fewer moving parts, so the list is shorter. Try these in order:

Close Mail and restart the iPhone. On an iPhone with Face ID, swipe up from the bottom of the screen and pause, find Mail, then swipe up on it. On an iPhone with a Home button, double-click the Home button first. Apple says to close an app only when it's unresponsive, so this is for a frozen Mail, not a habit.
Update iOS. Go to Settings > General > Software Update. The current version at the time of writing is iOS 27.0.1.
Find the account that causes it. Go to Settings > Apps > Mail > Mail Accounts, tap an account and turn off Mail (for iCloud, turn off "Use on this iPhone"). If the crashes stop, delete that account with Delete Account and add it again. Check your provider's website first that your mail is stored there.
Free up storage. Go to Settings > General > iPhone Storage. A nearly full iPhone can make apps unstable.
Delete and reinstall Mail. Mail is one of the built-in apps you can delete. Touch and hold it, delete it, then open the App Store, search for "Mail" by its exact name and tap Redownload. Deleting a built-in app also deletes its data on the iPhone, so make sure your mail is on the server first.

If Mail stays open but new mail stops arriving, see iPhone not getting emails. Our iPhone Mail guide and Apple Mail guide cover the other common fixes.

Sources

FAQ

Why does my Mac Mail app quit unexpectedly?

Usually a damaged message or mailbox index, one account that syncs badly, a Mail extension, or a macOS bug. If the alert names a plug-in, turn off Mail extensions first. Otherwise update macOS, rebuild the mailbox you were in and disable accounts one at a time.

How do I force quit Mail on a Mac?

Press Option-Command-Esc, or choose Apple menu > Force Quit, select Mail and click Force Quit. If the whole Mac is frozen, hold the power button for up to 10 seconds until it turns off.

How do I clear the Apple Mail cache?

Mail has no clear-cache button. The closest options are Mailbox > Rebuild, which downloads a mailbox again from the server, and reindexing Mail by moving the Envelope Index files out of ~/Library/Mail and letting Mail rebuild them. Back up with Time Machine first.

Will I lose emails if I rebuild a mailbox?

Not for IMAP and Exchange accounts: the mail stays on the server and downloads again. Messages kept only in On My Mac mailboxes, or in a POP account, live on your Mac, so back them up before you rebuild or reindex.

Why is Apple Mail so slow?

Often Mail is busy downloading or indexing, especially after a macOS update. Check Window > Activity (Control-Command-0). Erasing deleted items and junk, and archiving old mail, gives Mail less to handle.

Is Apple Mail down today?

Apple Mail is an app, so it can't be down, but your mail service can be. Apple's System Status page shows whether iCloud Mail is working. Google and Microsoft have their own status pages for Gmail and Outlook.

Why does Mail keep crashing on my iPhone?

Usually an outdated iOS version, one problem account or very low storage. Close Mail and restart the iPhone, update iOS, turn Mail off for each account to find the one causing it, and free up storage. As a last step, delete Mail and redownload it from the App Store.

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Mac Mail Keeps Crashing or Quitting Unexpectedly? How to Fix It