--On Samstag, August 20, 2005 00:17:38 -0400 "Stuart D. Gathman"
<stuart(_at_)bmsi(_dot_)com> wrote:
On Fri, 19 Aug 2005, wayne wrote:
> Then why are we giving PermError for other syntax errors and
> things like bad includes?
Well, for two reasons: First, it is a heck of a lot harder to
accidentally create a CNAME chain that is really long than it is to
accidentally type "ip:11.22.33.44" or "prt:foo.com".
adam.name SPF "v=spf1 a mx ptr ?all"
Adam: hey Bill, I've got this nifty SPF record that works for almost
any domain. Just make a CNAME to use it!
bill.name CNAME adam.name.
Bill: hey Carla! Check out this easy SPF record! Just CNAME it, and
it just works!
carla.name CNAME bill.name.
Oh, yeah, and since they use CNAME on the base of their zone, they can
*not* sepcify their own nameservers, MX records and so on. Except for
extremely trivial setups (mass provision of vanity domains comes to mind)
you can not do it this way.
If you need to set an SPF-RR you will also need an MX-RR or at least an
A-RR on the same name. While you might wish to alias the generic SPF-RR,
you usually do not want to do this for A- or MX-RRs. So for SPF using a
CNAME for names in different administrative domains will most certainly
break your mail setup (and probably your complete setup).
Ralf Döblitz