On Wed, 20 Sep 2017, Bakul Shah wrote:
Hi all. I've lurked here for a long time but hardly posted. I've only
used *nix for 25 years which makes me a n00b in these parts.
I run my own mail server and use trusted RBLs, Greylisting (GL) and
SpamAssassin (SA) in that order as I did many years ago.
I do some additional tricks like requring the sending MTA to hold the
connection open for (IIRC) 10 seconds before I will accept traffic. This
drives up spammers costs (and everyone elses :( ) but definitely helps.
I use postfix + postgrey. But greylisting doesn't
seem to work
any more. I detect spam using various scripts. As you put it,
I'd suggest GL works but not for the same reason it originally
worked.
GL is great in combination with an RBL. GL gives the RBLs time to get
updated so that by the time they get around to resending there is a better
chance the RBL will block the incoming spam. It's reall the combination
of greylisting and the RBLs which helps.
Perhaps not surprisingly the nature of spam has changed over the 20 years
that I've run my own MTAs (Sendmail and then Postfix). IMHO spam was most
difficult to deal with perhaps 5-10 years ago. It seems to me that the
enforcement against organised crime online in recent years has reduced
spam a lot. IIRC I read that in recent years most spam was coming from
only 7 or 8 organisations. When one of those was shutdown some years ago
I believe I saw a sudden drop in spam.
SA is probably of limited value today but it still catches some spam for
me. I never really bothered using a Bayesian filter inside SA or
standalone.
FWIW I spend virtually no time maintaining my MTA. I've been using the
same approach for about 10 years and if anything I get far less spam than
I did in 2007.
Cheers,
Rob