Find and Delete Large Mail Attachments on Mac

Why is Mac Mail taking up storage?

Mail keeps local data so messages and attachments are available to search and read. When inspecting storage with a disk space analyzer, the total can include downloaded messages, attachments managed by Mail, temporary Mail Downloads, and separate copies saved elsewhere. Account setup and download preferences affect what is kept on the Mac.

• Mail-managed message data belongs to the app. Treat its mailbox and database folders as app data, not cleanup targets.
• Temporary Mail Downloads are managed by Mail and follow its removal setting.
• Saved attachment copies are ordinary files in the destination configured in Mail. Removing one does not remove the attachment from the email.

Read more: Apple: Mail settings on Mac · Apple: Free up storage space on Mac

How do I check Apple Mail storage on a Mac?

Start with Apple menu > System Settings > General > Storage. Compare the Mail category with Mail's own account information, where your provider makes it available. An account's server usage is not necessarily the amount of local disk space it occupies.

1. Note the Mail amount shown in System Settings and which disk is selected.
2. In Mail, Control-click an account or mailbox and choose Get Account Info when available.
3. Open Mail > Settings > General and check the configured Downloads folder.
4. Let Mail finish syncing and give macOS time to refresh storage totals before comparing again.

Read more: Apple: Check email account storage in Mail · Apple: Free up storage space on Mac

Where does Apple Mail store attachments on Mac?

Mail uses a Mail Downloads folder under your user Library for temporary attachment downloads. Attachments you explicitly save go to the destination shown in Mail > Settings > General, which can be changed. Do not assume that destination is always ~/Downloads.

A saved attachment is a separate file you can review in Finder. Temporary downloads are managed by Mail. Their names or locations alone do not prove that a file is disposable, and Mail's internal mailbox directories can contain data and indexes the app needs.

Read more: Apple: Mail settings on Mac

How can I find large email attachments on Mac?

Use Mail's search and sorting instead of browsing its internal folders. Search for messages with attachments, then choose View > Sort By > Size. Review each message, sender, date, and attachment before deciding what to change.

For a saved copy, inspect the configured Downloads destination in Finder and sort by size. Use Quick Look or open the file to confirm what it is. If the attachment matters, save a copy to a backed-up location and verify that copy before removing anything from the message.

Read more: Apple: Search for emails in Mail on Mac · Apple: Mail settings on Mac

What happens when I delete an email or attachment?

Deleting a message removes it from that mailbox; account Trash settings determine how long it remains recoverable. For synced accounts, deletion may also sync to the server and other devices. Removing an attachment can have a different effect from deleting a separately saved copy.

Local On My Mac mailboxes may not have another server copy. Export or back up messages you need before changing them. A file saved to Downloads is separate: deleting that file does not remove the message attachment.

Read more: Apple: Mail settings on Mac

How can I reduce Mail storage without breaking Mail?

Find the source first, save attachments you want to keep, and make changes through Mail. Review Download Attachments in Mail > Settings > Accounts > Account Information to change what Mail downloads in the future.

1. Identify whether the space is in messages, temporary downloads, or saved copies.
2. Save and open any attachment you need to keep.
3. Delete only messages you no longer need, considering account sync and Trash behavior.
4. Use Remove Attachments only after checking whether the account is IMAP and whether you have a verified copy.
5. After syncing, recheck the same storage view. Changing download preferences does not authorize deleting existing Mail folders by hand.

Read more: Apple: Mail settings on Mac

Can Diskfern help find large Mail-related folders?

Diskfern can help place readable folders in the context of the wider storage map. It does not identify Mail-specific contents or report a Mail measurement for a particular Mac.

macOS privacy controls can limit access to Mail data. If a folder is unreadable, treat its size as unknown and use System Settings and Mail's own account and message views. Diskfern does not make Mail's database files safe to remove.

What should I never delete manually?

Do not remove random files from ~/Library/Mail, Mail's container, or internal mailbox folders. Finder cannot determine whether Mail needs those files, whether a message is local-only, or whether an attachment deletion will sync.

• Do not delete a whole folder just because its name contains Mail.
• Do not assume a saved Downloads file is a duplicate until you confirm the original message and backup.
• Do not empty Mail or Finder Trash until you have reviewed its contents and checked your recovery options.
• Do not use recursive Terminal deletion commands copied from cleanup advice.

Read more: Apple: Mail settings on Mac