Lost 'Bin' Folder in Mail

jcchk wrote:

This is useful but does not recover the bin folder associated with the email account.. Any other possibilities?

If you are not seeing in in All Trash—

For problem accounts the go to way to sort things out is to delete the account(s) from the Mail.app, then add it back.

Remove email accounts in Mail on Mac

Remove email accounts in Mail on Mac - Apple Support

Add email accounts in Mail on Mac - Apple Support

Add email accounts in Mail on Mac - Apple Support

Note—

IMAP accounts stay on the server, so no local loss, when you re-sync

POP accounts download and remove from the server—therefor save your inbox/sent box if you want them

“On My Mac" is just that, local folders you created and moved mail into. So no loss

Every Account has Server Settings. Verify your Setting for your 'problem account' if in doubt...

Mail>Settings>Accounts>Server Settings>Trash make any changes here more appropriate

jcchk wrote:

I seem to have lost my Bin for deleted emails in one of my accounts but not others. So I can't recover misplaced items and I can't erase the deleted items.

You can add or remove mailboxes, move your mouse pointer to the right side to reveal the + and use the dropdown...

ex "All Trash"

Mail User Guide for Mac