Dave Pooser wrote:
Which probably means Paul is blocking whatever server Verizon is using
for its
sender verification
Something I've seen before is a lot of mail servers will wait 10-45 seconds
before presenting an SMTP prompt to remote hosts; spambots typically won't
wait that long and give up. But since Verizon's sender verification (as of a
couple months ago; haven't checked recently) times out after 30 seconds,
that technique can have the side effect of making Verizon customers
unreachable.
What about sender verification of validity discourages spammers?
The only reason it works is that they are too lazy to actualy use some
random VALID forged return-path.
I for one would not like to force spammers to start using valid
return-paths. I dont need that blowback load. That would affect my
ability to read NANOG, hence its on-topicness.
IOW why isnt this technique (not pionered by verizon, afaik the
milter-sender was first I saw of it) short sighted and dangerous in the
long run?
And yes, put this together with sender-id/domainkeys/spf whathaveyou and
then its valuable. However thats not the world we live in now.
Joe
