I can't delete mailbox "On My Mac"

Not sure if you ever solved this but I stumbled upon your question after spending hours trying to do this myself.

I followed all sorts of advice - finding the mail folder, moving the mailboxes etc etc... But every time I re-opened mail they were still there and the files I'd moved were back where they started!

Anyway - turns out is really simple.....

Open Mail

Open Preferences (in the Mail menu)

Select the Accounts tab

Highlhight the account you want to delete

Find the + and - buttons to the bottom left of the window

Select the - button and volia! Pesky mailbox that has wasted far too much of my life already, is now gone!

Hope this stops you or someone else from wasting any more of your life on what's actually a really simple thing!

This worked perfectly. After over a year of using Mac Mail for my AOL account it suddenly went nuts. I figured that if I deleted the account and started over, as we often have to do on our cell phones, that all would be well.

The problem was figuring out how to delete the old account, and then I found this answer by doing a Google search.

I am pleased to report that the solution as described by Lucylastix is all that needs to be done.

After deleting the AOL account, I simply set it up again as a new mail box, everything is now working again as before, and I am back to not having to deal with the sluggish, ad laden AOL progam.

I looked at and tried every other "technical" reply, and oddly enough the simplest one is the one that worked. Thank-you.

That's why Apple hid the User's Library folder. :-)

Users that try to delete Time Machine backup files via the backdoor by going into the Backups.backupdb run into similar issues. The files will fail to delete from the trash and you can't put back.

Thank you SO much! You've saved me and my crappy week 🙂

Thank you so much. It really works. 🙂

Thank you! I wasted a month until I found your reply!!

Thanks Lucylastix

I had a mailbox I couldn't delete because it was linked to iCloud too, but I followed your process and got a prompt to delete it via iCloud and now I have.

Its been over three years since you posted this, but it was of great help to me as well. Thanks so much. It was an issue because it is an internet email account and tied to iCloud.