North American Network Operators Group
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Re: anybody here from verizon's e-mail department?

  • From: Joe Maimon
  • Date: Wed Feb 22 11:45:28 2006 
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