Alex,
Nice job. Here are some suggestions.
From http://www.vandenbogaerdt.nl/spf/wizard-help.html
... do a lookup on your MX server, then lookup the resulting A record(s),
then find the associated IP address(es). If you already know the IP
addresses and if these don't change often, it's better to put those
addresses in your record;
Minor clarifications: ...then lookup the resulting A record(s) to find the
associated IP address(es).
... better to put those addresses directly in your SPF record;
...
Always consider what a receiver needs to do if that receiver uses the
record that you created. Do so for email really sent by you but also
consider cases where a virus or a spammer abuses your name.
Add another paragraph:
Keep your SPF record simple. A list of "ip4" terms is all you really
need. "a" and "mx" terms may save you some effort updating your SPF record
when your "a" or "mx" addresses change, but this savings should be weighed
against the cost of multiple DNS queries on every message, especially spam
messages, which typically exercise every term in your record.
-- Dave
-------
Sender Policy Framework: http://www.openspf.org/
Archives at http://archives.listbox.com/spf-discuss/current/
To unsubscribe, change your address, or temporarily deactivate your subscription,
please go to http://v2.listbox.com/member/?listname=spf-discuss(_at_)v2(_dot_)listbox(_dot_)com