[Sussex] Greylisting Works

[John Crowhurst]

On Sat, April 26, 2008 10:09, Steve Dobson wrote:
> Hi All
>
> Spam has always been a problem, but for me (until about a year ago) not
> a particular burden.  In the end it is an ongoing arms race between the
> spammers and the e-mail admins, so I am always wary of new techniques to
> block spam in case they are quickly defeated.
>
> I had placed greylisting in that category.  The idea of temporally
> rejecting an incoming email is easy enough to understand.  Well written
> e-mail transfer software will just hold the message and try again later
> at which point it is accepted; spam-bots, that implement there own
> e-mail transfer software, just give up.  But I saw re-trying as being so
> easy  to implement that I didn't think greylisting would work for long.

Greylisting works well, it prevents about 99% of the spam from getting to
my server. It does have a downside, any script that sends mail directly
instead of using the local MTA will never succeed in sending you email.

-- 
John Crowhurst
John's Computer Support