On Sun, 18 Oct 2015 07:22:32 -0700 (PDT), Al wrote:

I want to set up an spf record for mydomain.co.uk, using this format:-

"v=spf1 a ip4:xxx.xxx.xxx.xxx -all" my question is what address to
replace x , the domain ip or the smtp server range.

Donno for sure but logic and sense says the IP of whatever machine is
trying to send mail for your domain.

Why not use "v=spf1 mx -all"?

Then if the mx machine(s) alter you don't have to worry about (aka
forget to) update your spf records.

--
Cheers
Dave.