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Re: [spf-discuss] How does SPF prevent forgery?

2006-02-16 17:43:37


Wally Winchester wrote:
Ah, that clears that up then - but leaves me confused, why (or when) is
it important to check 2821 addresses?

I could have answered more concisely: Its important to check 2821 if you want to reject the forgeries fast, instead of waiting for the entire email to waste your bandwidth.

That and, the 2822 is a mess of many headers that can be guessed at which one is the "real" domain of the email, hence why P in PRA stands for Purported

http://dictionary.reference.com/search?q=purported
Assumed to be such; supposed: the purported author of the story

Terry


WW

On Thu, 16 Feb 2006 17:31:54 -0500, "Terry Fielder"
<terry(_at_)ashtonwoodshomes(_dot_)com> said:

SPF checks 2821 addresses.  It makes no assertion about 2822 addresses.

Some would call 2822 address fakes "phishing", not forgery.

For 2822 checking, you should look at PRA (aka sender id). But there are serious caveats with using it, so be careful.

Terry

Wally Winchester wrote:

Hello.

If SPF only checks the envelope from address, how does it prevent
forgery?

i.e. how does it prevent a user getting an email From: 
person(_at_)bank(_dot_)com?

WW

--
Terry Fielder
terry(_at_)greatgulfhomes(_dot_)com
Associate Director Software Development and Deployment
Great Gulf Homes / Ashton Woods Homes
Fax: (416) 441-9085

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--
Terry Fielder
terry(_at_)greatgulfhomes(_dot_)com
Associate Director Software Development and Deployment
Great Gulf Homes / Ashton Woods Homes
Fax: (416) 441-9085

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