How to register SPF for a subdomain if its A record points to an IP different from that registered for the 2nd level domain?

Question

SPF

Hello.
The A record of the domen.com domain points to IP 1.1.1.1
, and the A record of the sub.domen.com subdomain points to IP 2.2.2.2
.
Thank you.

Answer 1

SPF records do not care what level your domain is, the main thing is that it lists the rules where it is indicated from where sending letters is allowed. If you were previously sending from addresses 1 and will continue to send the same way then nothing needs to be changed, if you will be sending from addresses 2 then add them to the permissions like this v=spf1 ip:1.1.1.1 ip:2.2. 2.2-all

Answer 2

https://www.mail-tester.com/ what advises here?