Tool for validating sender address as spam-fighting technique?

Chad Leigh -- Shire.Net LLC chad at
Sun Mar 11 19:43:25 UTC 2007

On Mar 11, 2007, at 1:36 PM, Kris Kennaway wrote:

> On Sun, Mar 11, 2007 at 12:41:48PM -0600, Chad Leigh -- Shire.Net  
> LLC wrote:
>> On Mar 11, 2007, at 6:31 AM, Justin Mason wrote:
>>> for what it's worth, I would suggest *not* adopting this
>>> as an anti-spam technique.
>>> Sender-address verification is _bad_ as an anti-spam technique,  
>>> in my
>>> opinion.  Basically, there's one obvious response for spammers
>>> looking to
>>> evade it -- use "real" sender addresses. Where's an easy place to  
>>> find
>>> real addresses? On the list of target addresses they're spamming!
>> This is a red-herring.  They already do that.  They have been doing
>> that for a long time.  And it has nothing to do with sender
>> verification.
>> Sender verification works and works well.
> I hate sender verification because it forces me (the sender) to jump
> through hoops just for the privilege of sending email to you.

No, it forces you to set up a correct RFC abiding system

> I send
> a lot of "courtesy" emails to e.g. port maintainers who have problems
> with their ports, and when I encounter someone with such a system I
> usually don't bother following up (their port just gets marked broken
> in the usual way, and they can follow up on it on their own if they
> want to).

If your system is following the RFCs then you should have no  
problems.  YOU should fix your broken system.  Sending emails without  
a valid from address is disconsiderate.  Why should I accept a mail  
from an account that violates the RFCs about accepting DSN back?


Chad Leigh -- Shire.Net LLC
Your Web App and Email hosting provider
chad at

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