[Mimedefang] Re: milter-greylist

Atanas mimedefang at asd.aplus.net
Mon Aug 30 17:33:54 EDT 2004


On Sun, 29 Aug 2004 Simon Standley wrote:

 > Just wondering ... has anyone tried running milter-greylist  ( See:
 > http://hcpnet.free.fr/milter-greylist/)  'in front' of MimeDefang?
 > If so, any comments re- success or otherwise?
 >
I tried that before thinking about using a filesystem. I thought of it 
as the fastest possible database backend, as it uses memory. But after 
running it for about 2 weeks in feeding mode it became the slowest one. 
  I found it using too much CPU, a Xeon at 2.4 simply was not enough and 
some SMTP sessions started timing out. This has happened at about 2 
million entries or so.

I liked the idea to use memory and started digging around. I found that 
it uses tail queues (# man queue) and the problem was it does linear 
searches on them, which is extremely inefficient for large number of 
entries and that's why it was taking so much CPU. There are better 
memory structures for that (hashes, binary binary trees, etc.), but I 
could not find an easier way to patch it.

In overall it's a nice package, it would work fine for me too if I had 
less number of emails to handle.

 > Only thing that seems to be missing from this milter is the white
 > listing of 'awkward' MTAs (as outlined in Atanas' 'File System based
 > solution to greylisting' recently posted on this list). Easily fixed
 > though.
 >
I'm sure there's a whitelist. As far I remember it's into the 
greylist.conf or something like that.

Regards,
Atanas



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