Something showed up today that I've never seen before.  Following up a
complaint about e-mail that never arrived, I found delivery attempts
in the sendmail log all day, each resulting in a greylist embargo.
The sender and recipient, the IP address, and the size of the message
were identical in each case.  When I finally checked the DCC log
files, I found that the body checksums were different in each case.
The message contained an application/ms-tnef attachment encoded in
base64.  Apparently, it was encoded slightly differently each time!
It was sent from Microsoft Exchange.  I'm amazed that this could even
happen.  Here's an example of the differences, excluding the headers:

 # diff 02/msg.3Q7APv 03/msg.3Q7BsP
 ...
 < eJ8+IikIAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEIgAcAGAAAAElQTS5NaWNy
 ---
 > eJ8+IikJAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEIgAcAGAAAAElQTS5NaWNy
 44c44
 < AQAhACcAAgBIAQEJgAEAIQAAADMyMjY5RkQzNUQ1NDE1NDM5NUIzRkI1MTA4OUE5NkM5ABAHAQOQ
 ---
 > AQAwACgAAgBYAQEJgAEAIQAAADMyMjY5RkQzNUQ1NDE1NDM5NUIzRkI1MTA4OUE5NkM5ABAHAQOQ
 68c68
 < APYQAAAAAEAABzComu8A6UPHAUAACDC6u7xXSUTHAQMA3j+fTgAAAwDxPwkEAAAeAPg/AQAAAAwA
 ---
 > APYQAAAAAEAABzComu8A6UPHAUAACDB5V5xwS0THAQMA3j+fTgAAAwDxPwkEAAAeAPg/AQAAAAwA
 84c84
 < AAAAVB8=
 ---
 > AAAAqh4=

-- 
-Gary Mills-    -Unix Support-    -U of M Academic Computing and Networking-
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