Storage Types

How to Clear Mail Storage on Mac

June 7, 2026·2 min read

Why Mail Takes So Much Space

The built-in Mail app on Mac downloads and caches every email attachment you've ever viewed. Over years of use, this cached data can grow to 5-10 GB or more. If you're trying to figure out how to clear storage on mac, checking Mail is often one of the most impactful steps.

Mail stores its data in `~/Library/Mail` and caches downloaded attachments separately.

Remove Unneeded Attachments

Open Mail and sort your messages by attachment size. Click **View > Sort By > Size** to find emails with the largest attachments. Delete emails with large attachments you no longer need, or save important attachments elsewhere before deleting the emails.

You can also select multiple emails with attachments, right-click, and choose **Remove Attachments** to keep the email text but free the storage used by attached files.

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Clear Mail Downloads Cache

Mail stores downloaded attachments in a separate cache folder. Navigate to `~/Library/Containers/com.apple.mail/Data/Library/Mail Downloads` using Finder's Go to Folder feature (**Cmd+Shift+G**). Delete the contents of this folder to reclaim space.

This won't remove attachments from your emails — they'll simply download again if you open them. This is a safe way to clear storage on mac without losing any email data permanently.

Rebuild the Mail Index

Over time, Mail's search index can grow large and become inefficient. Quit Mail completely, then navigate to `~/Library/Mail/V10` (the version number may vary) and delete the `MailData/Envelope Index` files. When you reopen Mail, it will rebuild the index automatically.

This process can temporarily reduce the mail app storage mac usage and fix search issues.

Consider Email Management Habits

To prevent Mail from consuming excessive storage in the future, periodically delete old emails with large attachments. If your email provider supports it, use server-side storage instead of downloading everything locally. This approach to how to clear storage on mac through better email habits keeps the problem from recurring.

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Frequently Asked Questions

How much space does Mail use on Mac?

The Mail app can use anywhere from 1 GB to 15+ GB depending on how many emails you have and how large the attachments are.

Will clearing Mail cache delete my emails?

No. Clearing the Mail Downloads cache only removes locally cached attachment copies. Your emails remain on the server and in the Mail app.

How do I stop Mail from using so much space?

Regularly delete emails with large attachments and clear the Mail Downloads cache. Consider using your provider's webmail for old emails.