importing very old email into kmail

hi, everybody . . . i keep a running archive, in maildir format, of email going back to my first days using the pre-1.0 beta of KDE. it's cool to have an occasionally useful. over the weekend i was finally able to copy email even older than that from my old OS/2 drive. (in case it's of interest, here's how i was able to do it. the drive was formatted hpfs, and the data were in a logical partition of 641mb -- the old drive was only 2.1gb. using an ide-usb adapter i was able to mount the drive but even with the hpfs kernel driver loaded it would not read. so i made a dd image of the partition and was able to then mount the image and everything was tickety boo.) the email came in via the MR/2-ICE (Mail Reader /2 Internet Cruiser Edition) email client. while the messages are not in maildir format -- i'm not even sure maildir existed in 1994 -- they are in individual files as is maildir. ingoing and outgoing messages are stored in the same directory, the former having an .RCV extension and the latter with an .OUT extension. if i click on one of either type, it pops up just fine in a kmail window, all fields populated accurately. my initial thought was to make a /MR2-mail subdirectory in my KMail mail directory, copy them all into that, then sort them into my currently existing folders as appropriate. but then i hit a problem: the .OUT files show up just fine, but the .RCV files don't. (best i can tell, they differ only in the extensions -- both, when clicked on, open in a KMail message window.) before i simply do a mass rename, i thought i'd see if there's some proper, approved method for importing such messages/files into KMail. i keep thinking that the method i'm using might cause my esiating email files to blow up or something. is there? -- dep Sent with ProtonMail Secure Email. Because privacy matters.