ietf-dkim
[Top] [All Lists]

Re: MX dot was (Re: [ietf-dkim] TXT wildcards SSP issues

2007-06-07 08:05:53

On Thu, 7 Jun 2007, Hector Santos wrote:

Example #1:

A company may want a I ALWAYS SIGN ALL DOMAINS, with NEVER exceptions after the b.c.d.foo.com subdomains:

   *._SSP               0  TXT   policy=ALWAYS
   *.b.c.d._SSP 0  TXT   policy=NEVER

Example #2:

A company may want a global NOMAIL, with exceptions:

   *._SSP               0  TXT   policy=NOMAIL
   _SSP                 0  TXT   policy=ALWAYS
   *.d._SSP             0  TXT   policy=NEVER
   d._SSP               0  TXT   policy=OPTIONAL
   c.d._SSP             0  TXT   policy=ALWAYS
   b.c.d._SSP           0  TXT   policy=OPTIONAL
   *.b.c.d._SSP 0  TXT   policy=NEVER

The client need only to do 1 query for the specific email domain provided.

Lets try some real test example queries for example #2 domain polices using the isdg.net domain:

email: isdg.net

        query --> _ssp.isdg.net
        This will return the ALWAYS policy (2nd record)

email: z.isdg.net

        query --> z._ssp.isdg.net
        This will return the NOMAIL policy (1st record)

email: d.isdg.net

        query --> d._ssp.isdg.net
        This will return the OPTIONAL policy (4th record)

email: q.d.foo.com

        query --> q.d._ssp.foo.com
        This will return the NEVER policy (3rd record)

Why would I look at q.d._ssp.foo.com rather then q._ssp.d.foo.com or
_ssp.q.d.foo.com?

--
William Leibzon
Elan Networks
william(_at_)elan(_dot_)net
_______________________________________________
NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html