A SPF record needs to be added to the domain record for websites that are sending outbound emails from an Ittrium server. Outbound emails can potentially be marked as SPAM if an email provider can not confirm the validity of the mail service through the SPF record.
There are several good resource to help you better understand SPF.
For general information about SPF record formats look here.
http://www.openspf.org/
For assistance generating SPF records for your domain, go here.
http://www.spfwizard.net/
You can also test your mail server to see if it is configured correctly at the following URLs.
http://www.kitterman.com/spf/validate.html
http://www.openspf.org/Why
The SPF record will look something like the following. Refer to the openspf.org website listed above to learn more about the various options
v=spf1 mx a ~all.
Complete documentation on the SPF record syntax can be found at the following URL.
http://www.openspf.org/SPF_Record_Syntax
Once you have created your record(s), you will need to add them through your domain name registrar. For Network Solutions, we added ours as TXT records (per network solutions instructions).