In
<Pine(_dot_)LNX(_dot_)4(_dot_)44(_dot_)0410241221110(_dot_)9378-100000(_at_)sokol(_dot_)elan(_dot_)net>
"william(at)elan.net" <william(_at_)elan(_dot_)net> writes:
If I have spf record "v=spf1 ip4:192.168.0.0/16 ptr -all" that would mean
its either 192.168.0.0/16 OR mail server with the domaini in reverse.
But lets I want SPF record that says mail that comes from example.com
domain MUST come from ip range 192.168.0.0/16 AND IT MUST come from mail
server that has PTR that domain. Can I enter this within SPF record? How?
Several comments:
First, I don't recommend using the ptr: mechanism. It is expensive.
Second, if you have control over your rDNS, which you must if you are
going to rely on the ptr: mechanism, you can just set up a naming
scheme like ptr:192_168.%{d}.
Third, if you are pondering more complicated logic operators, I say
"STOP! If you want java in a sandbox, you know where to find it."
Let's keep SPF simple.
Fourth:
example.com TXT "v=spf1 -include:_spf.%{d} +all"
_spf.example.com TXT "v=spf1 -ip4:192.168.0.0/16 -ptr +all"
This depends on email claiming to be from _spf.example.com being
rejected because it is an invalid host name.
-wayne