This document will attempt to record all root causes I've seen for
a "body of message has been altered" or "message has been altered"
DKIM verification result.


1. Incorrect use of Mail::DKIM's PRINT() method. The implementer fed
   the message in as it was received over SMTP, without reversing the
   "dot-stuffing".  So if the message contained any lines beginning
   with a period, the message would be signed or verified incorrectly.