Author: Felix Schwarz Date: To: Exim Mailing List Subject: Re: [exim] Bounce spam
Am 30.06.2016 um 08:40 schrieb John McMurray: > Below is an example. Is there anything I can do to prevent my users from
> getting these? I've searched as much as I can but I don't seem to see anything
> useful for this type of case. I might just be looking in the wrong places
> (search terms).
Well there are a few techniques like "bounce address tag validation" (BATV).
In our setup we just use rspamd (with just 1-2 rule tweaks) and it works
really well - all this "bounce-type" spam just gets filtered so I never
bothered to add more specific rules.
About 75% of our total spam volumes comes from dialup accounts or mail hosts
without valid reverse dns. All of them are caught by DNSBLs or just the "NO
HOSTNAME" rule.
Either way I think this is not so much exim related so you might want to check
out other anti-spam software (or maybe just a few additional rules) which can
be used with Exim.