Recovering a deleted mailbox

Data Recovery – Best

Data Recovery – Disk Drill

Data Recovery – Data Rescue

Data Recovery – File Salvage

Data Recovery – Stellar Phoenix

Data Recovery - uFlysoft

Data Recovery - Recovering Deleted Files

Data Recovery - Recovering Deleted Files (2)

See this article Create or delete mailboxes in Mail on Mac - Apple Support

Deleting a mailbox permanently deletes the mailbox and its contents, and can’t be undone. If you use Time Machine to back up files on your Mac, you can use it to recover previous versions of a deleted mailbox.

What type of email box did you have?

With pop you can let your email stay on the server it a configuration option

imap. always stays on the server.

microsoft exchange. I believe it stays on the server too.

R

You can try deleting the account and then add it back, but the mailbox is probably gone if it isn't in the Trash.