How to Delete Mail Storage on Mac: Complete Cleanup Guide (2026)

If your Mac is running low on storage, the Mail app could be one of the biggest reasons. But how? The short answer is that your emails, attachments, and cached data are stored locally on your system, even after you delete them, and take up to several GB. To tackle this, many users wonder how to delete Mail storage on Mac step by step.

If you’re here, then you’re probably one of those searching for the same solution. I believe your search ends here. In this guide, I’ll walk you through tried-and-tested methods to clear Mail storage on Mac safely, without risking your important emails. Plus, I’ll also show you how to manage IMAP-based email data efficiently to avoid issues like IMAP folder is not properly syncing and storage overload in the future.

How to Check Mail Storage on Mac?

Before diving into the methods to delete Mail app storage on Mac, let’s first understand what is actually taking up space in the Mail app. Storage is consumed by:

• Email messages
• Large attachments
• Archived emails
• Other mailbox data

Now, if you’re wondering how to check Apple Mail storage space on Mac, follow these simple steps:

1. Click on the Apple Menu and go to About This Mac.
2. Tap “Storage” from the top.
3. Select Manage from the top-right corner.
4. After this, press the Mail button.
5. Selecting Mail will automatically display the storage used by Mac Mail.

In these simple steps, Mac users can check their Apple Mail storage limit and determine if it is full or not. Now, have you ever wondered why Mac Mail is running out of storage? If yes, but you don’t know the answer yet, don’t worry, next I’ll explain the same step by step. 

Why is Mac Mail Running Out of Storage?

Receiving a warning that Mac Mail storage is full can prevent users from accessing their Mail inbox data. In such cases, it’s important to check what’s consuming your Mail storage.

Storage fills up because:

• Attachments, i.e. PDFs, images, and videos, are stored locally
• Emails are cached for offline access
• Deleted emails still exist in hidden folders
• Mail logs and temporary files keep increasing

Many users also face issues like IMAP server timeout or syncing errors when their mailbox becomes overloaded.

Many users often ask: “Do inbox emails take up storage? Yes, Definitely. Emails occupy the space, mostly with large-sized email attachments. 

Moreover, users can remove unimportant or unwanted emails from their inboxes to clean up the space instantly. For the same, next I’ll share how to clean Mail storage on Mac with all the possible solutions step by step.

How to Delete Mail Storage on Mac?

To clear Apple Mail storage on macOS, users can either empty the Trash or delete Junk emails. Removing large attachments is another way to free up space on Mac Mail. Additionally, users can set email rules to tidy or clean their inboxes.

Now, let’s walk through these solutions and some advanced tricks in detail to free up mail storage on Mac. Besides this, we will find out the ways to manage the attachment settings to prevent these storage issues. So, move ahead to learn the effective approaches to organising mail storage.

#Method 1. Delete Mail Attachments from Mail Downloads Folder

One of the quickest and most effective ways to free up Mail storage on Mac is by clearing the Mail Downloads folder. Whenever you open or preview attachments in the Mail app, macOS automatically saves a copy of those files in this folder.

This method is completely safe because it only removes locally stored copies of attachments, not the emails themselves. 

Here are the steps to delete mail storage on Mac:

1. 1. Open Finder
   2. Click Go > Go to Folder
   3. Paste this path:
      ~/Library/Containers/com.apple.mail/Data/Library/Mail Downloads
   4. Press Enter
   5. Select files:
      • Press Command + A to select all
   6. Move them to Trash
   7. Empty the Trash

When you follow these steps accurately, without skipping any of them, it will help you to remove locally downloaded attachments, while emails remain intact in the Mail app. After cleaning up, check your storage; you’ll see the freed space in GBs.

#Method 2. How to Delete Mail Storage on Mac by Removing Mail Cache Files

Another effective way to free up Mail storage on Mac is by deleting Mail cache files. These are temporary files that the Mail app creates to load emails faster and provide quick access to your mailbox data. However, over time, these cache files keep growing in size and can occupy a significant amount of storage. 

Removing them helps clear unnecessary data and can also improve the performance of the Mail app. To do so:

1. Open Finder
2. Go to:
   ~/Library/Mail/
3. Open the latest version folder:
   • Example: V10, V9, etc.
4. Locate:
   • Cache files
   • Temporary files
5. Delete unnecessary cache files

Do NOT delete entire mailbox folders unless you have a proper backup. 

#Method 3. How to Clear Mail Storage on Mac by Deleting Attachments

Deleting attachments directly from the Mail app is another practical way to free up Mail storage on Mac without removing your emails. Even a few emails with heavy attachments can consume several gigabytes. By removing these attachments, you can keep the email content intact while freeing up valuable space on your Mac. 

This method is especially useful if you want to clean up selectively. Here’s how:

1. Open the Mail app
2. Use the search bar:
   has:attachment
3. Sort results by Size
4. Open large emails
5. Right-click attachment > Remove Attachment

This is useful when managing large IMAP mailboxes or before performing tasks like export IMAP to PST for backup.

#Method 4. Empty Trash and Junk Mailboxes

Emptying the Trash and Junk mailboxes is one of the simplest ways to free up Mail storage on Mac. Many users assume that deleting emails removes them permanently, but that’s not true. Instead, those emails are moved to the Trash or Junk folders, where they continue to occupy storage space. 

To remove them, follow these instructions:

1. Open Mail
2. Select:
   • Trash
   • Junk
3. Click:
   • Mailbox > Erase Deleted Items
   • Mailbox > Erase Junk Mail

Deleted emails still consume storage until they are permanently erased. So, don’t overlook this approach, as this simple method helps to free up mail storage on Mac in GBs.

#Method 5. How to Delete Mail Storage on Mac by Disabling Automatic Attachment Downloads

Disabling automatic attachment downloads is a smart way to prevent Mail storage from filling up in the future. By default, the Mail app downloads all attachments automatically, which can quickly consume storage.

To resolve this:

1. Open Mail
2. Go to Settings (Preferences)
3. Click Accounts
4. Select your email account
5. Set:
6. Download Attachments > None or Recent

This solution helps you to ensure your attachments are downloaded only when needed.

#Method 6. Remove and Re-Add Mail Account

If your Mail storage is still unusually large even after trying all the basic cleanup methods, removing and re-adding your Mail account can be an effective solution. Because the Mail app stores excessive local data that is difficult to clean manually, including:

• Cached files
• Downloaded attachments
• Offline email copies
• Sync data and temporary files

This resolves syncing issues and prevents errors like IMAP authentication failed or mailbox corruption.

To do so, here are the steps to follow:

1. Open System Settings
2. Go to Internet Accounts
3. Select your email account
4. Click Remove Account
5. Restart your Mac
6. Add the account again

It helps you to delete all local mail data, and don’t worry, your data is secure on the server. That means whenever you re-add the account, all your data will be downloaded from the server, so there is a 0% chance of data loss.

Advanced Cleanup (Optional)

If, above all, the manual methods won’t work, then try these advanced fixes:

#1. Delete Old Mailboxes

1. Open Mail
2. Right-click mailbox
3. Select Delete Mailbox

#2. Remove Duplicate Messages

• Search for duplicate emails manually
• Delete unnecessary copies

#3. Clean Spotlight Index (if Mail size shows incorrectly)

Run in Terminal:

sudo mdutil -E /

How to Delete Mail Storage on Mac – A Smarter Way to Manage and Free Up Mail Storage on Mac 

While manual methods work, they can be time-consuming with multiple email accounts or large mailboxes. As per my experience, instead of manually locating and deleting files from different hidden folders, opting for an automated utility provides a centralized and structured way to manage your email data. For example, if you want long-term storage management, you can backup Apple Mail to external hard drive or archive data safely.

For the same reason, I suggest trying SysTools IMAP downloader for free. 

It allows you to back up entire mailboxes from IMAP-based accounts such as Gmail, Outlook, Yahoo, and others, so you can safely remove unnecessary data from your Mac without the risk of losing important information.

Why Consider SysTools Email Downloader?

If your Mail app is consuming excessive space, it usually means your emails and attachments are stored locally. With the SysTools solution, you can:

• Save data in formats like 
  • Windows: PST, PDF, MBOX, EML & MSG
  • Mac: PST, PDF, MBOX, EML, EMLX, TXT, MSG, CSV, HTML, & MHT
• Remove emails from your Mac after backup to free up space
• Maintain folder hierarchy and metadata
• Apply date filters to archive only old emails
• Works with modern authentication (OAuth 2.0) for Microsoft 365 and G Suite.

This means you can keep your important emails safe while removing unnecessary data from your system.

How to Backup Mac Mail Locally?

Download the specified utility for free, and follow these steps to free up mail storage on Mac by backing up data locally:

• Step 1. Open the solution, and select the output file format, i.e. PST, PDF, MBOX, EML & MSG.

• Step 2. After selecting the desired file format, mark the Email box, and leverage the Date Filter option for specific data export (if needed).

• Step 3. Now, select the IMAP Server for Apple Mail.

• Step 4. Afterwards, in the destination window, click the Backup folder path button to select the location where you want to save the resultant data.

• Step 5. In the Users window, use the mapping options to maintain the hierarchy, i.e. Import Users & Download Template.

• Step 6. When you validate your permissions, hit the Start Backup button to initiate the backup process.

Tips to Manage the Mac Mail Storage

There is no doubt that the task of delete Mail storage on Mac is not easy. Therefore, it is suggested that Mac users implement free and simple storage management tips to prevent the issue of Apple Mail storage being full. Now, read the best practices to manage the space:-

• Clean the large-sized mail attachments, one of the effective ways to manage the inbox. With this, users can avoid the warning messages of Mac Mail’s storage being full.
• Unsubscribe from the unwanted newsletter, allowing users to make their mailboxes clutter-free. Another benefit of this tip is that Mac users access only important emails in the Mac mailbox.
• To manage the storage, users need to clear the Junk items and promotional email messages. Removing these emails instantly frees up storage space and streamlines the inbox.
• Avoid downloading unnecessary files
• Use cloud links instead of attachments
• Limit sync duration (e.g., last 30 days)
• Archive emails instead of storing locally

Author’s Verdict

Mail storage can silently consume a lot of space on your Mac’s disk. The biggest storage gains come from:

• Clearing the Mail Downloads folder
• Removing large attachments
• Emptying Trash and Junk regularly

If you combine these methods on how to delete mail storage on Mac, you can easily reclaim 5–20 GB of storage without affecting your emails.

People Also Ask

Q. Does deleting emails free up storage on Mac?

No. You have to delete them from the empty Trash and remove attachments.

Q. Is it safe to delete Mail cache files?

Yes, cache files are temporary and safe to remove.

Q. Why is Mail taking so much space?

Because of:

• Attachments
• Cached data
• Multiple synced accounts

Q. Will deleting Mail data remove emails permanently?

Only if emails are removed from the server (IMAP/POP settings matter).

Q. Do Mac Mail emails take up storage?

Yes, email messages occupy the space, especially large-sized email attachments. Additionally, Junk or promotional items also occupy the space. Therefore, deleting these attachments enables users to manage the storage of Mac Mail.

Q. How to get rid of Apple Mail storage on Mac?

To delete the emails on Mac, clean the unwanted emails and attachments. Besides this, empty the Trash folder in your Mail app.