Milter-greylist

i have think to this : 

 using a hash function like md5 on ip/from/to info 
 could be a good mean to
 - speed up (to check) the matching process
 - limit memory fragmentation (compared to futur string allocation in
replacement of the fixed ADDRLEN siwe)
 - limit memory consumation
 - limit .db size and speed up dump/reload process

 it is a bit like the SYN Cookie mechanism :

 when a new attempt arrive, compute something like
 hash = md5(apply_subnetmatch(ip),from,to)
 and just check if this 'hash' value exist in the whitlist table ...
 or create it

 in this hash table, the real value (ip,from,to) are optionnal
attributes. you can keep them for readability / debugging purpose
 or forget about them for performance.

 you can also dump only the hashes instead of full ip/from/rcpt in the
greylist.db and reload them from this file too. ip,from,to are optionnal
 
 off course, having the ip/from/to info is esayer to read !!
 but on a BIG mail server whith millions of user... memory consumation
can be a problem.

 the hash could also be compute only on ip or ip+from, depending of
the lazy/strict policy we want.


 L.

 --
Laurent FACQ - facq@... (05.40.00.65.34) - Reseau REAUMUR /
Bordeaux