21 Sep
2017
21 Sep
'17
6:55 a.m.
On Wed, 20 Sep 2017, Grant Taylor wrote:
I thought I had heard reports that tar pitting, for
the purpose of
slowing spammers down, didn't achieve much.
Dunno, as I've never used it, but there are some clever tricks that can be
used to enforce RFC-compliancy (a lot of spamware is written by idiots who
don't understand the finer points of SMTP):
Enforce proper DNS configuration e.g. must resolve etc, and must
actually exist.
Make 'em wait a few seconds before sending your own banner, and drop
the connection if they send beforehand.
Set up an enormous greeting banner (many long lines); there is nothing
in the RFC that says it has to be a single short line.
These simple measures alone cut out most of the crap; the rest are handled
by various DNSBLs and my private access list.
--
Dave Horsfall DTM (VK2KFU) "Those who don't understand security will
suffer."