Hi Popowich, sorry for the horrendously late reply, I got stuck on another project. I would rather use the names than the IP's, as the IP's may rarely change and the names will not. In which case, would either of these SPF records work? I am unsure of the correct use of the a: or mx: which is the main difference between the two. Also, I'm new to the record itself so other options such as the soft and hard bounce values are a bit of a Grey area to me too.
Thanks for the help.