[GTALUG] Spam is basically dead

[ac]

On Wed, 16 Aug 2017 08:40:03 -0400
Myles Braithwaite 👾 <me at mylesb.ca> wrote:
> ac via talk wrote:
> > 1. Bounce when no rDNS (exim/postfix/sendmail/qmail - 2 second
> > conf)  
> Sometimes people don't have access to configure Reverse DNS (or PTR)
> as they are sending with a dynamic IP address. This isn't common but
> at least for GTALUG there are five or six people who host their email
> from their home on dynamic IP addresses.
> 
I did not say the reverse must match the forward. But the vast majority
of email servers are dropping if no reverse zone as hijacked IP
ranges do not have reverse zones.

Dynamic IP numbers from your ISP usually/mostly have reverse zones. But
to operate a real email server you will need a fixed IP number anyway
for your own sanity

So, if you do not want spam - drop if no reverse zone (rule 1)  :)


> > 2. Use 10+ dnsbl with properly configured spamassasin (cache
> > locally) - with 2 (or more, or less) points per dnsbl listing 
> > (five minutes copy & paste for exim/postfix)   
> > -> dnsbl from here: http://multirbl.valli.org/   
>
> I stopped using SpamAssasin a while ago. I know use Rspamd, Rmilter,
> and OpenDMARC. I found SpamAssasin was letting in way to much spam and
> required way to much knowledge to run properly.

Which is why you use 10+  (If you do not want spam) 

If anyone applies the 6 rules - Spam is dead :)

I have now worked with email for 30? years... and in that time I have
seen that domains to do not have the same spam, so there is no magic
single rbl, and spam trends change all the time. For new clients I
always lookup the spam their domains get on around 300
International Blacklists, then build a short list of 15 -20 and
then measure effectiveness of those against their incoming, these days
it always works and spam is actually dead. 

Okay, well you still get the occasional manual sent spam from a public
email account by some opportunist, but I mean that the senseless junk 
is all gone... 

Andre