Is your email domain hosted with Godaddy?
I came across these steps on their site:
Log in to your GoDaddy account and click on the domain you want to modify.
On the DNS Management page, at the bottom of the Records section, click Add and select TXT from the menu.
Host - Enter the host name for the TXT record. For example, type @ to map the record directly to your domain name, or enter the subdomain of your host name (labeled Host), such as www or ftp.
Fill the TXT Value field with SPF record for Swiftpage: v=spf1 a mx ip4:184.108.40.206/26 ip4:220.127.116.11/24 ~all
Select how long the server should cache the information. This is called TTL (Time to Live).
* Swiftpage does not provide support for DNS modification. If you are unsure how to add this to your DNS contact Godaddy.