John Johnson said:
The stock response to this is "well, change ISP" -- but that's a naive
view of most of the world, where the choice is not available. In my case
(in Ireland), accessing the net through this ISP was 2/3 the price of its
nearest competitor.
Complaining is not working? Do they even answer your requests?
I'm sure that you are aware that paying them rewards them for
not following standard practices.
True -- but see above. When a much stronger impetus (much cheaper net
access) applies, the details of their SMTP infrastructure is not as
important. (Cheap net access in Ireland, BTW, means "under $100 a
month", cf http://www.irelandoffline.org/ ;).
(BTW in terms of other systems issues (uptime, reliability etc.) they are
pretty excellent; it's just this one issue I've been able to pick them
up on.)
in other words 35.59% of spam has no rDNS, but 3.05% of ALL nonspam mail
does too. The latter is bad news, it's a *very* high false positive rate.
Spam outfits have a habit of targeting secondary mail servers
(higher MX value). By just introducing rDNS checks on our
secondary mail server, we cut down on a huge amount of wasted
connections.
That's a good technique, actually. I can see that working without FPs
(until your primary MX suffers an outage that is ;)
--j.
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