How to fix import errors in the Mail application?

This is happening to me as well, and there is plenty of storage space on my Mac.

Maybe my Mail database is too big? Nearly 200k messages...

But it used to work well until yesterday, today suddenly an import is necessary (and since it fails, Mail is not running anymore).

This worked for me...

Restart in Safe mode and try again the import:

Start up your Mac in safe mode – Apple Support (UK)

I followed some of the information in this thread and fixed it very easily by simple unchecking Mail from all the Internet Accounts in System Preferences except for iCloud. I started Mail it started instantly with only 257k and then I right-clicked on the iCould inbox folder and selected Sync Mail with iCould. It went to work and did its thing. Lastly I brought back all my other internet accounts online. Easy peasy :)

updated to Sonoma 14.1 then got this mess… - Apple Community

I get the same "Import Failed" message. I have 1.95TB of unused space. Got new M1 Macbook to replace old 2011 Macbook which was using Outlook -- which now requires a subscription. I copied everything to new M1 Mac via TimeMachine. I don't know what the M1 Mac Mail thinks it needs to import. Is there something somewhere I can just "blow away" and start over? I do still have access to the old 2011 Macbook...

I was in the same predicament. I finally gave up and contacted Apple Support (in Sweden) and a very skilful and helpful guy helped me through the problem. To solve the problem I had to cancel all three mail accounts I have in System settings. Be sure that you have all data about your accounts stored somewhere or printed out so you can reregister again.

After that I started Mail app again and now it launched but of cource with very few data.

Then I registred the account from my internet provider (but leaving the two accounts which were private domains) and all of a sudden the import begun.

Then we tried to reenter one of the other accounts, but failed when using the private domain email adress. We then changed to the ”original” account (used for redirecting incoming and outgoing mails) which is from the same provider as in the first attempt. Now this account also showed up and imported all stuff related, but as the ”original"email account. The same procedure with the last account was successful, and now I’m very glad that everything is up and running.

So there is some some mismatch between Sonoma and my private adresses which I have to figure out with my domain service provider.

Of course there is a lot of things to sort out (layout, delete old stuff, move certain mailes to right folders etc) before all is back to ”normal” again.

It's a corrupted mailbox.

What worked for me was to go to Library/Mail, then in the current version folder, move any file ending in .mbox to a desktop folder. Re-import files a bit at a time after that.

Hi iraayeed,

Thank you for using the Apple Support Communities! For this error, you'll want to ensure you follow the guidance below to free space on your Mac:

Free up storage space on your Mac

If you continue to receive the error, we recommend that you reach out to Apple Support directly to take a further look. Please reach out here:

Apple Support

Hope this helps!

Have a great day.

What a worthless piece of advice! Bunch of worthless auto answer bots on this Apple forum. The guy said he has 250GB of free space!

Don't dis the Apple staff. They are not bots.

The OP may have 250 GB of remaining storage but the kind and volume of email being imported may be of the wrong format or (potentially) larger that the remaining available storage including temporary storage needed for the import process.

I have the same problem.

Mail just stopped working (freezes).

I tried deleting Envelope* files, and it fails with the above message.

Now, I can no longer open Mail the new way or the old way (restoring the Envelope* files).

AAAAAgggggggghhhhhhhh

Yes! The idea to go in and move all the account folders that contain the .mbox files was genius @Don_DYL!

I moved all the account folders (using Mail v10) out of the V10 ~/Library/Mail/V10/MailData folder to my Desktop and Mail reopened without trying to perform another failed import on startup.

Thanks for the great advice!

I have the same problem, email was working fine for the last 2 weeks and now I get the "Failed Import". Searching the WEB I have found no fix. Have you had any luck?

I have the same problem - just happened overnight....after a system update

Restarting in Safe Mode and rerunning Apple Mail worked for me.

MacBook Pro with Sonoma 14.3.

Thanks bevance!