Ok here is the odd situation I'm in.
Lotus's FTP site does not like Fetch, but the Finder worked well enough, and I was able to get ccMail 6.1 PPC Mac. So I installed it. Of course it didn't make an enclosing folder, so it just dumped all of its files right into my Applications folder. But once I cleaned that up, I am able to open the program....
but ccMail is not a normal mail program. When you open it, the first thing it does is ask you for a login and password. There is no server. It's weird. I am able to "pick" my post office, and I can select the local files from the ccMail 2 data files. That might actually work, but here's the catch. Even though it's local mail, you still need to log in with a username and password to access it. ccMail 2 is still auto-filling the username and password from 25 years ago. I'll need to type it again fresh for ccMail 6. But I don't know it. And the customer doesn't know it. So this looks like it might be a dead end all over again. Plus it looks like this version of the app IS scriptable! If only it worked.