spf-discuss
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Re: Re: 'explain' etiquette, or is this a security concern?

2004-04-20 11:45:47
In <87pta2r0b4(_dot_)fsf(_at_)athene(_dot_)jamux(_dot_)com> "John A. Martin" 
<jam(_at_)athene(_dot_)jamux(_dot_)com> writes:

"Wayne" == Wayne Schlitt

    Wayne> The explanation text is a way for domain owners to
    Wayne> communicate with the users of their domain.

    Wayne> Consider the case of [extreme example deleted]

Is this a solution looking for a problem?

Good question.  I think the answer is "no, it is a useful solution for
a non-trivial number of people".

I took a look at some old SPF adoption roll data.  While only about
0.5% of the domains had exp= modifiers, many of them give specific
information that legitimate users would likely want to know.  For
example, one lists a toll-free number call, another lists the contact
email address to help resolve problems.  Some list domain-specific
websites to visit.

There were a few that aren't particularly helpful, such as the
chepelov.org example you found.  


    Wayne> Again, the only people who will see the explanation text
    Wayne> are spammers and such who have forged the domain name and
    Wayne> legitimate users of the domain name that need to be given a
    Wayne> clear explanation *to them* about the correct use of the
    Wayne> domain name they are using.

And anyone else that can listen to what is on the wire.

Uh, I guess if you are worried about people who can wire-tap your
connection *AND* they will get confused by SPF explanation texts *AND*
this confusion will cause you serious problems, then I think it would
be best for you to reject all SMTP connections that don't use
STARTTLS.


I'm pretty anal about security issues, but I'm having a hard time
seeing this as a problem.


-wayne