On Wed, Jun 29, 2005 at 04:30:59PM -0400, John Hinton wrote:
I would also like to include an example of a 'shortest least
restrictive' entry. For instance.. would this work?
ew3d.net. IN TXT "v=spf1 a mx +all"
That's too much.
You allow "a", "mx" and the rest of the world. That's like saying:
it can be red, green or any other color. Shorter: it can be any color.
This is the shortest:
ew3d.net. IN TXT "v=spf1 all"
Any host will match "all", inclusing the "a" and "mx" records.
The "+" modifier is default. The result: any host is allowed
to send mail on behalf of ew3d.net users.
Just to show the two ends of the spectrum, even though +all or all
should not be the 'suggested' choice.
You want two ends? This is the other:
www.ew3d.net. IN TXT "v=spf1 -all"
Nobody will ever send out mail as
"(_dot_)(_dot_)(_dot_)(_at_)www(_dot_)ew3d(_dot_)net" nor will this
domain (www.ew3d.net) be used in HELO/EHLO.
In this case "-" is necessary.
Alex