How to Remove Mail Cache on Mac

What Causes This?

Apple Mail stores local copies of messages, attachments, previews, and search index data so it can open your inbox faster and work offline. Over time, that cache can grow very large, especially if you use multiple accounts, receive lots of attachments, or have old synced mailboxes. If the cache becomes bloated or corrupted, Mail may feel slow, use excessive storage, or behave unpredictably.

Common Symptoms

• The Mail app is slow to open, search, or switch between folders
• Mail is using several GB of storage on your Mac
• Messages or attachments do not load correctly
• Search results in Mail are incomplete or inaccurate
• Mail freezes, crashes, or constantly re-downloads messages

How to Fix It Manually

1. Quit Apple Mail completely

   • Open Mail.
   • Click Mail > Quit Mail from the top menu, or press Command + Q.
   • Make sure Mail is fully closed before deleting cache files.

2. Open your user Library folder

   • In Finder, click Go in the top menu.
   • Hold Option, then click Library when it appears in the menu.
   • This opens the hidden ~/Library folder for your account.

3. Delete Mail cache files

   • In the Library folder, open Containers.
   • Find and open com.apple.mail.
   • Open Data > Library > Caches.
   • Move the contents of this Caches folder to the Trash.
   • Go back to ~/Library and also open the main Caches folder.
   • If you see folders related to Mail, such as com.apple.mail, move those to the Trash too.

4. Remove downloaded Mail data if needed

   • In ~/Library, open the Mail folder.
   • You may see a folder such as V10, V11, or another version number depending on your macOS version.
   • Inside it, look for folders like MailData or large cached message data.
   • Do not delete random mailbox files unless you understand what they do. If your goal is just clearing cache, focus on obvious cache-related files such as envelope index rebuild targets or temporary data.

5. Rebuild Mail indexes if Mail search is broken

   • In the MailData folder, look for files named:
     • Envelope Index
     • Envelope Index-shm
     • Envelope Index-wal
   • Move these files to the Trash.
   • When Mail opens again, it will rebuild its message index automatically. This can take time if you have a large mailbox.

6. Empty the Trash and restart Mail

   • Right-click Trash in the Dock and choose Empty Trash.
   • Reopen Mail.
   • Wait while it re-creates cache and re-indexes messages.
   • Check whether storage use, search, and app responsiveness have improved.

7. Restart your Mac if Mail still acts strangely

   • Click the Apple menu > Restart.
   • After rebooting, open Mail again and test it.
   • If messages are missing temporarily, give Mail time to resync with your accounts.

Fix It Automatically with Kudu

If you do not want to dig through hidden Library folders, Kudu can scan for bloated app cache, temporary files, and other junk safely. It helps you recover storage and improve responsiveness without guessing which files are safe to remove.

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