If you just want to use the MX records and A records to control who is valid, then <code>"v=spf1 mx a -all"</code> is the text record that works. This [http://www.spfwizard.net/ wizard] can help. Once you're done, you can check on things with
; Check the MX records<code>nslookup -query=mx</code> or ; Check records for example.com using Google's nameserver<code>nslookup domain example.com 8.8.8.8</code> ; Check text records (including SPF) for example.com<code>nslookup -type=txt example.com</code>
== Resources ==