Hello Dataosk,
I have the SPF Record on my site and all of my customers sites.
I just pasted the same on all - since I needed nothing fancy.
You just add to your DNS Zone for each domain - too easy !
Worth it - It is surpose to be ! and on the DNS Report - it gets a pass
DNS Zone Line to enter:
Domain = domain.com.au
TTL = 14400
Record Type = TXT
Info = "v=spf1 a mx ~all"
Hope that Helps
Brad