[Mimedefang] suspicious characters

[Michael Fox]

I'm trying to understand what triggers the setting of
$SuspiciousCharsInHeaders and $SuspiciousCharsInBody?  All I can find are
circular definitions that vaguely mention possible exploits.  But no
specifics are given.  Before I use either of these, I'd like to understand
better what constitutes "suspicious" in both cases. 

 

So, can someone provide a concrete/specific definition of "suspicious"
characters in headers?   In the body? 

 

Also, what do others do?  

Do you bounce every message that for which $SuspiciousCharsInHeaders is
true?

How about every message for which $SuspiciousCharsInBody is true?

 

Thanks,

Michael