MacOS Mail in Catalina – cannot create new mailboxes in IMAP accounts

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Level 2

348 points

MacOS Mail in Catalina – cannot create new mailboxes in IMAP accounts

I'm on a new Mac and I've added several work email accounts (all IMAP) to Apple Mail in addition to my iCloud account. I cannot add a new mailbox to any of the IMAP accounts, only the iCloud account. Whether I use the + button at the top of the Mailboxes column or use the menu command in the Mailboxes menu, nothing happens. I can only add new mailboxes to iCloud and On My Mac.

I will also note that the Mailbox display seems to have changed in Catalina; previously only the account inboxes were listed under the INBOX dropdown at the top, and all mailboxes/folders inside the IMAP accounts were listed below in the column. Now it appears that all mailboxes in an account are listed under the Inbox dropdown -- except for iCloud which still gets a dedicated dropdown at the bottom. If it's not supposed to look that way then I have a serious problem!

FWIW, I used Mail on an older Mac running Mojave and I was able to add a new mailbox to one of the accounts with no problems.

JVK

MBP 16", 2.4 8 core, 64GB, 1 TB, Mail 13.4, Catalina 10.15.4

MacBook Pro

Posted on May 26, 2020 1:34 PM

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Answer 1

Top-ranking reply

Barney-15E

Level 10

116,140 points

May 26, 2020 3:10 PM in response to John Knowles

Oh, well. Someone else here may be able to give a good value for the Path Prefix. Maybe [INBOX]/

But, I really don't know.

Who hosts the email servers? Is it a company or are you hosting them yourself?

Might be able find something on their website.

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Answer 2

Barney-15E

Level 10

116,140 points

May 26, 2020 1:49 PM in response to John Knowles

The folders being listed under Inbox is not a new thing and it is not what Mail expects or can deal with very well. Mail won't let you create a mailbox within the Inbox, so if that is where all of yours are showing up, then that is likely why you cannot create a new one.

I think you can adjust that with IMAP Prefix Path in the account preferences in Mail, Advanced IMAP Settings button.

I don't know what you need to set for the path, though. Maybe your IT department knows.

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Answer 3

John Knowles Author

Level 2

348 points

May 26, 2020 2:34 PM in response to Barney-15E

Thanks for the reply, @Barney-15E! Appreciate it.

Yeah, I thought the new sidebar arrangement was weird. I feel like I didn't even have to set this up in prior versions, the mailboxes just went where they were supposed to. And IT Dept. is ME so I have no idea what to set that prefix path to either.

I just chatted with Apple support and they wanted to escalate me to Engineering -- but only after I upgrade to 10.15.5. Can't do that in the middle of a project I'm on and it's not even clear if that will fix the issue.

JVK

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