How do I return recovered mailboxes from my desk top back to time machine?
I don't think you need to; the restore copies the files rather than moving them.
I have a list of recovered files taking up space on my desktop. I want them moved back to time machine if possible. If I just delete them, will they still exist in time machine or am I permanently deleting them?
On time machine, "Restore" brings the recovered files to your mail desktop. I want to now remove them.
Go back to TM star wars display and find the files. If they restore again then the backups are still present and you can delete the desktop/mail stuff.
Retrieving data ...