Storage shows 172 GB used by Mail 16.0 (Macbook Pro, Tahoe 26.7.1). I am unable to free the space. There is an Import folder which cannot be removed "On My Mac." Is there a way to use Terminal to find/delete the offending folder, or perhaps I should uninstall Mail?
Apple Mail Using 172 GB of Storage on a MacBook Pro
Apple Mail 16.0 is reportedly using 172 GB of storage on a MacBook Pro running macOS Tahoe 26.7.1. The main issue is an Import folder under On My Mac that cannot be deleted.
The goal is to find out what's taking up the space, protect any important messages, and resolve the problem without damaging other mailboxes or macOS.
1. Don't Try to Uninstall Apple Mail
Apple Mail is built into macOS and isn't intended to be removed like a third-party application. Removing or reinstalling the app would not necessarily free up the space occupied by stored emails, attachments, or imported mailboxes.
The problem is likely with the stored mail data, not the Mail application itself.
2. Check Whether Import Is Responsible for the 172 GB
Open Mail, expand On My Mac, and select Import. If it opens, check whether it contains a large number of messages, oversized attachments, or additional submailboxes.
Also consider whether the problem started after importing messages, restoring a backup, or updating macOS.
The 172 GB shown in System Settings → General → Storage doesn't prove that Import accounts for all that space. Other local mailboxes, attachments, cached data, or Mail database files may contribute.
Messages under On My Mac are stored locally and may not exist on an email server, so take care not to delete the only copy of anything important.
Apple's guidance:
3. Back Up Important Messages
Before attempting further cleanup, preserve any messages you may want to keep.
If possible, select Import and choose Mailbox → Export Mailbox. Save the exported mailbox somewhere safe, preferably on an external drive. If exporting isn't available or fails, make a Time Machine backup and verify that your backup is accessible.
This is particularly important for imported messages that may not be recoverable from an email provider.
4. Try Deleting Import Through Mail
Once your messages are backed up:
See Apple's instructions: Create or delete mailboxes in Mail on Mac.
If Delete Mailbox is unavailable, greyed out, or fails, note exactly what happens. The cause could relate to the mailbox type or a Mail database problem; the name Import alone doesn't tell us why it cannot be deleted.
Restart your Mac and try once more. If it still fails, don't keep repeating the attempt or manually delete internal Mail files.
5. Would Rebuilding the Mailbox Help?
Mail offers Mailbox → Rebuild for certain mailbox problems. It can refresh the index and help with some display or message-list issues.
However, rebuilding does not normally remove stored messages or attachments, so it is unlikely to reclaim 172 GB by itself. Consider it only if the mailbox opens but appears to have indexing or display problems.
6. Check Storage After Cleanup
If you successfully remove unwanted messages or the Import mailbox, give macOS some time to update its storage figures. Then revisit System Settings → General → Storage.
If Mail still reports approximately 172 GB, other mail data may be responsible, or the storage figures may not yet reflect the changes.
You can also use View → Sort By → Size in Mail to help locate large messages.
Apple's guides:
7. If Import Still Cannot Be Deleted
If the mailbox remains undeletable after restarting, contact Apple Support rather than risk damaging the Mail database.
Explain that Mail 16.0 is using approximately 172 GB, that Import is under On My Mac, and that the mailbox cannot be deleted. Tell them whether it opens, whether Delete Mailbox is disabled or produces an error, and whether the problem began after an import or software update.
Avoid manually deleting Mail's internal files or using third-party cleanup tools until the cause is understood and a reliable backup is available.
Bottom Line
The key is to establish whether Import is responsible for the 172 GB and why Mail refuses to remove it. Apple Mail is part of macOS, so uninstalling it isn't the solution.
Start by inspecting Import, backing up anything important, and trying the supported deletion procedure. If that fails again, contact Apple Support before attempting more aggressive cleanup. This gives you the best chance of recovering the storage without losing important messages.
Apple Mail Using 172 GB of Storage on a MacBook Pro
Apple Mail 16.0 is reportedly using 172 GB of storage on a MacBook Pro running macOS Tahoe 26.7.1. The main issue is an Import folder under On My Mac that cannot be deleted.
The goal is to find out what's taking up the space, protect any important messages, and resolve the problem without damaging other mailboxes or macOS.
1. Don't Try to Uninstall Apple Mail
Apple Mail is built into macOS and isn't intended to be removed like a third-party application. Removing or reinstalling the app would not necessarily free up the space occupied by stored emails, attachments, or imported mailboxes.
The problem is likely with the stored mail data, not the Mail application itself.
2. Check Whether Import Is Responsible for the 172 GB
Open Mail, expand On My Mac, and select Import. If it opens, check whether it contains a large number of messages, oversized attachments, or additional submailboxes.
Also consider whether the problem started after importing messages, restoring a backup, or updating macOS.
The 172 GB shown in System Settings → General → Storage doesn't prove that Import accounts for all that space. Other local mailboxes, attachments, cached data, or Mail database files may contribute.
Messages under On My Mac are stored locally and may not exist on an email server, so take care not to delete the only copy of anything important.
Apple's guidance:
3. Back Up Important Messages
Before attempting further cleanup, preserve any messages you may want to keep.
If possible, select Import and choose Mailbox → Export Mailbox. Save the exported mailbox somewhere safe, preferably on an external drive. If exporting isn't available or fails, make a Time Machine backup and verify that your backup is accessible.
This is particularly important for imported messages that may not be recoverable from an email provider.
4. Try Deleting Import Through Mail
Once your messages are backed up:
See Apple's instructions: Create or delete mailboxes in Mail on Mac.
If Delete Mailbox is unavailable, greyed out, or fails, note exactly what happens. The cause could relate to the mailbox type or a Mail database problem; the name Import alone doesn't tell us why it cannot be deleted.
Restart your Mac and try once more. If it still fails, don't keep repeating the attempt or manually delete internal Mail files.
5. Would Rebuilding the Mailbox Help?
Mail offers Mailbox → Rebuild for certain mailbox problems. It can refresh the index and help with some display or message-list issues.
However, rebuilding does not normally remove stored messages or attachments, so it is unlikely to reclaim 172 GB by itself. Consider it only if the mailbox opens but appears to have indexing or display problems.
6. Check Storage After Cleanup
If you successfully remove unwanted messages or the Import mailbox, give macOS some time to update its storage figures. Then revisit System Settings → General → Storage.
If Mail still reports approximately 172 GB, other mail data may be responsible, or the storage figures may not yet reflect the changes.
You can also use View → Sort By → Size in Mail to help locate large messages.
Apple's guides:
7. If Import Still Cannot Be Deleted
If the mailbox remains undeletable after restarting, contact Apple Support rather than risk damaging the Mail database.
Explain that Mail 16.0 is using approximately 172 GB, that Import is under On My Mac, and that the mailbox cannot be deleted. Tell them whether it opens, whether Delete Mailbox is disabled or produces an error, and whether the problem began after an import or software update.
Avoid manually deleting Mail's internal files or using third-party cleanup tools until the cause is understood and a reliable backup is available.
Bottom Line
The key is to establish whether Import is responsible for the 172 GB and why Mail refuses to remove it. Apple Mail is part of macOS, so uninstalling it isn't the solution.
Start by inspecting Import, backing up anything important, and trying the supported deletion procedure. If that fails again, contact Apple Support before attempting more aggressive cleanup. This gives you the best chance of recovering the storage without losing important messages.
Yes, you can likely reclaim that space by removing the folder, but I would not delete it outright just yet.
From your screenshot, the folder is part of Apple Mail’s local storage, and the Data directory alone is using about 133.48 GB.
That is a substantial amount of space, and it is likely where most of the problem lies.
Here’s what I would do before considering a macOS reinstall:
One caution: Mail manages its own internal databases, so manually removing this folder can cause syncing issues or lead Mail to recreate the data. Renaming it first gives you a safer way to test, though it is not risk-free.
It was not the Import folder(s), the majority of the hidden data was under that 0746FD9C... folder, which I renamed, as you suggested. Opened Mail and all was fine. Closed Mail and pulled that folder and all its subfolders to the Trash. Mail was still fine, so I emptied Trash. There were over 1,500,000 items, probably all emails. The Mac I migrated data from was 7 years old (the reason to buy a new one), so things were being collected and I did not notice. A simple rm -rf command in Terminal would have been easier than all the clicks I had to do in Trash, because each sub-sub-folder was "in use", but I think it would require root permission to get to the hidden directory. Anyway, I recovered about 150G of the 170 being wasted by Mail. I'll work on the other 20G later.
I'm just an old Unix user, sorry, I like Macbooks but miss having control with nothing hidden. Thanks for the help.
willymca wrote:
I tried all those suggestions, even before I posted the problem here. I think the problem may have happened during the migration from my previous Macbook Pro. This Macbook is new, just arrived a few days ago. I really don't care about the emails. I just want to recover disk space. 170GB is too much for mail. It is more than all my documents and apps put together. So, if the solution is to re-install Tahoe, migrate again, so be it, but I suspect the result will be the same.
If the goal is to recover the 170 GB of disk space, I’d first confirm that the space is actually being consumed by Mail data.
>> Reinstalling macOS over the existing installation generally won’t remove locally stored emails or attachments. <<
If you decide a complete reset is the best option, use Erase All Content and Settings (available on supported Macs with Apple silicon or a T2 Security Chip).
This erases user data, settings, and installed apps while retaining the currently installed macOS.
Before proceeding, back up anything you want to keep.
After the reset, set up the Mac as new rather than using Migration Assistant to transfer everything from your previous Mac.
Reinstall your apps and copy back only the documents and other files you need.
This approach should eliminate the migrated Mail data if it is responsible for the storage usage.
However, it won’t guarantee that the problem is solved if the underlying cause is something else.
I’d verify the Mail folder’s actual size first, so you don’t have to reset a brand-new Mac unnecessarily.
willymca wrote:
Storage shows 172 GB used by Mail 16.0 (Macbook Pro, Tahoe 26.7.1). I am unable to free the space. There is an Import folder which cannot be removed "On My Mac."
172 GB is huge for a mail folder...
You can not delete the folder, however you can select all (Command A) and delete the content within the folder.
have you tried the normal ways of removing mail accounts on the macos email app?
Add and manage email accounts in Mail on Mac - Apple Support
How do I remove an account from Mac Mail … - Apple Community
more
Yes, I removed the Gmail account in Mail. I also tried removing all accounts entirely from Mail, then using Gmail's internet interface to delete all emails, past and present, then return to Mail, reset the account and see the same storage being used by Mail.
I tried all those suggestions, even before I posted the problem here. I think the problem may have happened during the migration from my previous Macbook Pro. This Macbook is new, just arrived a few days ago. I really don't care about the emails. I just want to recover disk space. 170GB is too much for mail. It is more than all my documents and apps put together. So, if the solution is to re-install Tahoe, migrate again, so be it, but I suspect the result will be the same.
Ok, before I go the re-install route, I did some more digging and a "hidden" directory is where I think the used disk space may exist. Since I don't care about any emails I may remove, can I safely remove the 0746FD9C... folder?
Unable to remove Mail Import folder on MacBook Pro
