How to Delete Mail Attachments on a Mac to Free Space

In short: Mail can quietly hoard gigabytes of downloaded attachments on your Mac. Here is how to find the biggest ones and remove the local copies safely. Your messages stay on the server, and everything you delete goes to the Trash so it is easy to undo.

If your Mac feels tight on storage, the Mail app is a common and often overlooked culprit. Every attachment you open or preview gets downloaded and cached locally, and over months of PDFs, photos, and slide decks, that can add up to several gigabytes. The good news is that removing these local copies does not delete your actual email. In most setups your messages live on the server (iCloud, Gmail, or Exchange), so a downloaded attachment you clear locally can be re-downloaded any time you need it again.

Below is a calm, step-by-step way to find the biggest offenders and reclaim the space, without touching anything you should not.

First, check how much space Mail is using

Before you delete anything, get a baseline so you know it worked. Open the Apple menu, choose System Settings, then General > Storage. Wait a moment for the bars to calculate, then look for the Mail row. Click the small info icon next to it to see a breakdown. On macOS Sonoma and Sequoia (14 and 15) this is the most reliable built-in view of what Mail is holding on to.

You can also open Mail and use Mailbox > Erase Deleted Items and Erase Junk Mail for a quick, safe win. Emptying the trash and junk mailboxes is genuinely reversible only up to the point you empty it, so make sure nothing you want is sitting in there first.

Find the biggest attachments inside Mail

The most direct approach is to let Mail show you the largest messages, which are almost always the ones with heavy attachments. In Mail, click into a mailbox, then use View > Sort By > Size. This puts the chunkiest messages at the top. Scroll through and you will quickly spot the emails carrying big photo bundles, video clips, or design files.

You can also search deliberately. Click the search field and type a term, then use the Attachments filter that appears in the search bar to narrow results to messages that actually carry files. This helps you review by sender or subject before you act.

Remove just the attachment, keep the message

Here is the part people miss: you do not have to delete the whole email. Select a message that has an attachment, then choose Message > Remove Attachments. Mail strips the downloaded file but keeps the text of the message. The email stays in your mailbox, just lighter. If you ever need the file again and it still lives on the server, you can re-download it.

To clear several at once, select multiple messages (hold Command and click each, or Shift-click a range), then apply Remove Attachments to the whole selection.

Clear the local downloads folder Mail keeps

Separately from messages, Mail keeps a folder of files you have opened from attachments. When you double-click an attachment to view it, a copy lands in a Mail Downloads folder and often stays there long after you are done. Clearing it is safe because these are throwaway copies, not your only version.

In Finder, choose Go > Go to Folder and paste this path: ~/Library/Containers/com.apple.mail/Data/Library/Mail Downloads. Look through the folder, and drag anything you no longer need to the Trash. These are temporary downloads, so removing them will not affect the emails themselves. If a file listed there is something you actually want to keep, move it into your Documents folder first.

A quick word on safety and privacy

Two habits keep this kind of cleanup stress-free. First, favor reversible deletes. Everything you drag to the Trash sits there until you empty it, so if you clear the wrong thing you can put it back with File > Put Back. Avoid tools or commands that permanently erase files on the spot. Second, be skeptical of any cleaner that wants to phone home. A tool that tidies local files has no real reason to send data over the internet, and you can confirm that for yourself with a firewall like Little Snitch, which shows you exactly what is trying to connect.

Reversibility is your safety net. As long as removals go to the Trash, a mistake is a minute of recovery, not a lost file.

If you would rather automate the tedious part

Doing this by hand works, but if you clean up regularly, a good app can preview the junk first and let you send it to the Trash in one pass. For a free option, CoreSweep is our top pick: it is free forever with an optional one-time Pro upgrade ($49), ships with zero telemetry, and every removal goes to the Trash so it stays reversible. A strong, cheaper runner-up is SkoonMac, which is also free with a one-time Pro at just $19. Either way, the principle is the same as the manual steps above: preview first, keep it to user-level junk, and never permanently delete when the Trash will do.

Once you have cleared attachments and the Mail Downloads folder, revisit the Storage screen to confirm the number dropped. A few minutes of tidying here often frees up more space than any other single cleanup on a Mac.

Frequently asked questions

Does deleting Mail attachments on a Mac also delete my emails?

No. Removing a downloaded attachment clears the local copy but keeps the message itself. In most setups your email lives on the server (iCloud, Gmail, or Exchange), so if you need the file again you can re-download it any time.

Where does Mac Mail store downloaded attachments?

When you open an attachment, a copy is saved to a hidden Mail Downloads folder at ~/Library/Containers/com.apple.mail/Data/Library/Mail Downloads. These are throwaway copies, not your only version, so clearing them is safe and does not affect the emails.

Can I recover a Mail attachment after I delete it?

Yes, as long as you send it to the Trash rather than erasing it permanently. Items sit in the Trash until you empty it, and you can restore a file with File then Put Back. Keeping removals reversible is the safest way to do this cleanup.

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