Macmail

Hi all, 2 q's;

1). On upgrading my 2015 MacBook pro to big sur, mail suddenly had separate junk mailboxes for each account, and no default bin for my 5 accounts.

Yesterday I accidentally deleted 'All Inboxes' at the top, which was very handy in viewing all messages at once.

So, now I have to click on each mailbox to see messages.

How do I get 'All Inboxes' back so i can see them all in one place again?

2).

Even if i edit each accounts junk and bin folders' settings set to a master one for each, there are still multiple.

4 accounts are imap, one pop, if that helps.

Thanks in advance :-)