After upgrading to Big Sur, I no longer have a Trash or Junk mailbox in Mail. Where did they go? How do I get them back?

It should be shown under the account for which it exists.

You can ctrl-click on any mailbox in the Accounts and choose "Add to Favorites"

Essentially, favorites are tied to what is shown up at the top of the Mailbox list as opposed to just showing the "unified" mailboxes.

Also, while this is still the same, you likely have a "Trash" or "deleted items" mailbox on your email server. In the account Mailbox Behaviors in Preferences, you can set whether you want to use the server mailbox or the On My Mac mailbox for Trash (and other things).

I think what he might mean, I see it too, is that under favorites there used to be a combined mailbox for both trash and junk (just like there is for all inboxes, all sent, etc.) That is no longer present. Yes I can move my four email account's trash mailboxes to favorites but they are not combined like they should be.

This does not work for me. I normally receive many emails in my junk folder, which I check periodically for the occasional ones that run afoul of the spam filter. I have not had access to these since I upgraded. Likewise the trash folder.Adding the junk mailbox to favorites does nothing. Can I reverse the upgrade?

Move your mouse pointer to the right side of Favorites until you see a + sign and click on it. You'll get the possibility to add a box that combines all trash boxes from different accounts

Create a new Smart Mailbox:

There is also 'All bins'.

Dear mulberry58

Many thanks for guidance. Issue resolved.

I was actually trying to add the trash and junk mailboxes by clicking on + sign shown on right of On my Mac. 🥴

Cheers

You’re welcome

😉

You’re so right, thanks