If your ISP is Dreamhost following these instructions to add Swiftpage SPF:
https://help.dreamhost.com/hc/en-us/articles/216106197-How-do-I-add-an-SPF-record-
You will need to add the following to your DNS:
v=spf1 a mx ip4:64.78.151.128/26 ip4:216.241.183.0/24 ~all
36812 What is an SPF record and how do I get one?
http://kb.act.com/app/answers/detail/a_id/36812/kw/SPF%20Record