mailboxes missing but in library envelope no help

[KayFisher]

Suddenly I am missing many (maybe 20 or 30) mailboxes.
I can find them all in ~Library/Mail/V3/Mailboxes
I have tried deleting all the ~Library/Mail/V3/MailData/Envelope... files and restarting mail
No help.
Any idea how I can get these mailboxes to again re-appear in my mail?

 

[Shirasaki]

Does deleting account and adding back to reconfigure a viable option for you?

 

[dianeoforegon]

Try adding the step to remove the mail containers folder...

In User's Library > Containers, drag com.apple.mail.com to trash.
Delete the envelope files again.
Lot out under the Apple in the Menu bar
Log in and open Mail.

 

[jbarley]

Seeing as how no one has suggested this I will, try The Rebuild command, under Mailbox in the top menu.

 

[Lobwedgephil]

On mail, under On My Mac, click on show to the right of it. For some reason set to hide on GM.