KioqKioqKioq OR fixing mutt's base64 problem

So I've occasionally been getting *really* useful email messages such as:
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Not having the slightest clue as to what was causing it - I'd simply return them to the sender and ask for help... sadly the senders generally didn't know what it was either.

It turns out that the sender's setup is incorrectly labelling these emails as 8bit... when it's actually been encoded in base64. To fix it:

1. Save the email to its own new folder (just so there's only one email in the file to edit).
2. Open it up in a plain text editor (eg vim)
3. Update the header line that reads:
   Content-Transfer-Encoding: 8bit to
   Content-Transfer-Encoding: base64 - save and close
4. Navigate to the folder in mutt and read away happily.