I have a single server
Domain: mycompany.com Server: mail.mycompany.com MX: mail.mycompany.com
Would this record work
"v=spf1 ip4:38.28.xx.yy a:mail.mycompany.com mx:mail.mycompany.com ~all"
Use simple:
"v=spf1 mx -all"
and test it(http://www.kitterman.com/spf/validate.html)