Extract emails from a text file

[Leslie Williams]

I have an imap server at home to handle my email. Here is how things
normally work:

fetchmail -> postfix -> procmail -> cyrus-imap -> thunderbird

I made a typo when I was editing my ~/.procmailrc file, and as a result
all emails that didn't get filtered before the typo got put into a
single text file in my home directory.

Any ideas on how I can get these emails back into imap? I've tried
fiddling with both postfix and procmail as well as moving the file into
thunderbird's local folders.  So far nothing has worked.

-Leslie