[SA-exim] [exim] Greylisting algorithms after end of DATA

[Chris Lightfoot]

On Sat, Jan 13, 2007 at 02:37:07PM +0100, Magnus Holmgren wrote:
> In fact, nothing prevents us from using an arbitrary set of header fields 
> (such as Subject, Message-ID, From) in constructing the key, if it gives 
> better confidence in what we want to know: whether the other end retries 
> after a temporary failure. (We could even accept delivery and whitelist based 

Identifying messages in this way is obviously in some
sense not adequate, since you can always put any
message-ID on any message; and some messages don't have
message-IDs at all. I don't know whether that level of
sophistication will matter versus the current behaviour of
spammers. If it does then looking at the kinds of hashes
that things like `Vipul's Razor' use is probably a good
idea.

-- 
``Odd things, animals.
  Dogs look up to you. Cats look down to you.
  Only pigs see you as an equal.'' (Churchill)