I use Mail and like it quite a bit. My only problem is that it sometimes loses track of how many unread messages there are.

I can't imagine why anyone would specifically like OE, but to each his own.

Anyway, pine is a Unix text-based mail client. There may be a binary version available for MacOS X somewhere, or there may not, in which case, you'll have to compile it on your own, which may require installing the developer tools if you've not already done so. ISTR that pine compiles up fairly easily.

I'm not in front of an OSX machine now (obviously), but a quick google turns up the fact that Mail keeps its folders in mbox format, which is a format pine can understand. I can't seem to find exactly where it keeps them, but look in your home directory. It should be fairly obvious, I'd imagine.

Anyway, once you've got pine runnning, you'll have to tell it to look at Mail's folder:

1. Make sure you quit Mail first, then copy the Mail folder file somewhere else (so you don't accidentally modify it), somewhere like /Users/username/mbox.
2. Now start pine in a Terminal window and enter its configuration screens (SC from the initial screen).
3. Then change the inbox path to the full pathname of that Mail folder's file that you just copied (/Users/username/mbox or whatever).
4. Also find the option called enable-aggregate-command-set and enable it.
5. Exit the configuration screen and confirm everything. You might have to exit and restart pine at this point; it'll tell you if you do.
6. Now go into the INBOX (press I from the initial screen).
7. Select all the messages you need to requeue using the ; command. There are some reasonably advanced searches here that might be useful to you, or you could just select each one individually.
8. Once you've selected all the messages (they should be marked with an X at the beginning of the line), press A to issue a command that will affect all of the selected messages, then press B, which will ``bounce'' all of them.
9. It'll ask you to enter an email address to bounce them to; enter your email address whose messages get delivered to the POP server you want them to requeue into. It'll ask you to confirm (do so) and it'll send them all.

The only thing I can think of that might make this not work is if Unix mail sending isn't set up right on MacOS X by default. I don't think that's the case, but if it doesn't work, go back into the config screen and set the smtp-server to whatever you'd normally set it to under Mail or OE or whatever and try again.