Need help setting SPF records

Hello!

I need some help getting some SPF records set up.

We are running our outbound mail and root domain from Comcast IPs. Our MX servers are hosted at MXLogic and are not used as outbound mail servers.

I believe I need an SPF record on the outbound server to relay mail from our web server (Rackspace hosted IP), our dev web server (Comcast hosted IP), and our email marketing server (Comcast hosted IP). I'm assuming we need to set this record on the outbound mail server's FQDN itself for all three server IPs as permitted senders. Am I correct in this thinking? And also - is it necessary to include our local IP range for local users sending mail? IE 10.1.2.x. I'm concerned about the local IP range since it does show up as the first "Recieved by:" source in the final destination mail headers.

Then I need to set the main SPF record for the domain to allow only the outbound server as a permitted sender. Not sure if the IPs from the first SPF record are necessary here, it seems like they would be redundant.

I can PM all the needed info to whoever responds to this.

Thanks!!!

Dustin Binge