Saving messages from expired POP accounts in Mac Mail - advice please!

Jan 16, 2009
Reaction score
Mac user for 15 years, but trying to consolidate the mess of Mail...

On the left sidebar, under the “MAILBOXES” section I have the following tabs:
Each of these contains a subfolder for each of my POP3 accounts.

Then, under the “ON MY MAC” section, I have a few folders, each corresponding to a different email account, and containing subfolders mirroring the folder structure of the online mail account. Most of these are old expired Yahoo accounts, which I think I imported into Mail way back when.

I understand that MAILBOXES is for those connected to my online POP accounts and ON MY MAC is for old messages only stored locally.

So my questions:

1. Quite a few of my old POP accounts are no longer used. They exist in the MAILBOXES section but not the ON MY MAC section. I want to ensure the messages are safely stored locally, and then remove the accounts from my MAILBOXES section. So I think I just need to move/copy the accounts from MAILBOXES to ON MY MAC.

I can create an ON MY MAC entry for those accounts (New Mailbox --> location On My Mac), but when I manually drag messages from the MAILBOXES section into it, they all get lumped together in a single folder.
a) how do I create the Inbox/Sent/etc. subfolders within it?
b) by dragging messages from MAILBOXES to ON MY MAC am I actually moving their location on my computer, or just designating them within Mail as "safe/offline"?

2. A couple of the expired accounts already appear in ON MY MAC, a relic from when I tried to organize my mail folder during a new Mac setup about 10 years ago, and was dragging and dropping folders in my Finder (!). Should I simply drag and drop messages from MAILBOXES to these ON MY MAC folders to sort out these accounts?

Thanks in advance for any advice, or link to such basic information!

Shop Amazon

Shop for your Apple, Mac, iPhone and other computer products on Amazon.
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.