Internetworkers: http://www.ibiblio.org/internetworkers/

["Brian Godfrey" <bjgodfrey AT gmail.com>]

SPF is a text record that is tied to your DNS.  It's not really a spam stopping tool so much as a direct list of all servers allowed to send email on behalf of your domain.  It will keep someone from spoofing your email address if you set it up correctly.  Many spam sloutions out there check for SPF records. 

 

Here is how our DNS entry looks

 

@       IN   TXT   "v=spf1 ip4:66.162.193.196 ip4:66.162.193.195 ip4:209.61.184.105 ip4: 69.20.55.131 ip4:69.20.55.132 ip4:69.20.55.137 ip4:213.191.74.141 ip4:213.191.74.144 ip4:213.191.74.145 ip4:212.100.225.180 ip4:213.165.187.66 ip4:194.204.113.148 include:gfi.com -all"

 

You can read up some more on SPF from http://spf.pobox.com

 

Brian

 

On 4/19/06, Steven Champeon <schampeo AT hesketh.com> wrote:

on Wed, Apr 19, 2006 at 10:28:40AM -0400, Jason Tower wrote:
> i have a spf record for my domain, i don't have an effective way to gage
> its effectiveness but it's trivial to set up if you have control over
> your dns.

That's true.

> ; <<>> DiG 9.3.1 <<>> cerient.net txt
>
> ;; ANSWER SECTION:
> cerient.net.            86400   IN      TXT     "v=spf1 a -all"

And that's meaningless. It just says "mail from this domain might come
from anywhere with a cerient.net hostname". Nothing stops me from
publishing a PTR defining my IP as 'foo.cerient.net'.

> i believe that most of the big boys in email (aol, yahoo, gmail, etc)
> are doing spf lookups and enforcement.

Nope. They may be doing lookups, but nobody is doing enforcement, not
even hotmail (who just give you a scary warning if the sender lacks SPF
or SenderID records).

> however, i don't know how easy
> it is to enforce spf on a mail server that you might run yourself,
> haven't really bothered to look.  but that's a secondary issue, if you
> have active domains you should definitely set up a spf record for
> yourself.

If you want to give the impression that SPF works, matters, and is
picking up steam, by all means. Unfortunately, it's not going to help.

> i have three clients whose domain was used in forged spam
> email and it was a major headache for them, spf records likely would
> have at least mitigated the problem.

Or not.

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