[NCLUG] spam help

[Bob Proulx]

Jake Edge wrote:
> Bob Proulx wrote:
> > Within a domain it is individually controllable by email address.
> 
> the latter (controllable by email address) is not correct as i 
> understand things, either the domain has a set of legal sending hosts or 
> it doesn't ...

You can control SPF on an address by address basis.  One way is with
the 'exists' mechanism.

  http://new.openspf.org/SPF_Record_Syntax#exists

I use this feature to allow a few selected email addresses to have
SPF effectively disabled.  Here is my SPF record.

  $ dig proulx.com txt +short
  "v=spf1 a exists:%{l}.spf.proulx.com -all"

I have a couple of addresses for which I completely turn off all SPF
checking.  The actual addresses are not important but for example
let's say I wanted bob at proulx.com to be allowed any sending IP.  I
would enter any IP address, such as 127.0.0.2, as the IP for
bob.spf.proulx.com.  Because that exists (if I added it) the lookup is
matched and there is no restriction.  I don't have a bob.spf record
but I do have records set up for other addresses that I wish to allow
without restriction.

Bob