I found an old backup from my school days.
In it are a bunch of emails I wrote and received with the mail-app in BeOS.
Is there a way to restore them to a modern mail-account (IMAP or POP3), so that I can transfer them to my regular mail-archive?
In ye old Be times I used to copy my mails from account A to account B just copying them into a IMAP folder of B, not tested in haiku but it could work
It seems that Mails are files, so you can copy them on FAT disk, rename them as *.eml and Drag"nDrop files in Thunderbird application. I think it should work.
Renaming them to .eml let me import them into Thunderbird.