anybody here from verizon's e-mail department?

Joe Maimon jmaimon at
Wed Feb 22 16:35:06 UTC 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.


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