A SPF (Sender Policy Framework) is a way to allow you to restrict
which mail servers are allowed to send email for your domain name.
An example of an SPF would be : example.com. TXT "v=spf1 -all"
SPF records are TXT records placed into a domains DNS. To setup a SPF record we recommend using the following link:
http://www.openspf.net/dns.html
Please note, forwarding emails can sometimes break the SPF. If this
is the case we reccomend using SRS (Sender Rewriting Scheme). More
information about this can be found here:
http://www.openspf.net/SRS
If the above links do not work please see http://www.open-spf.org/Tools/
***** Additional notes for Webservio customers:
If you are using Webservio Strata Mail email systems the SPF should be :
"v=spf1 a mx ip4:208.82.180.0/22 ip4:208.82.180.50 ip4:199.15.255.0/24 -all"