Hello,
I'm having a headache of a time with my SPF record. I have validated with various tools and it checks out at least in terms of format/syntax.
The SPF record for the domain has ip4 addresses in CIDR. The sending IPs fall within a range of /24 for example however I'm still getting the below. It could be a mail relay or other server but it's not indicated via CIP in the message header. I only have the originating/source IP and evidence is presented within the header.
Received-SPF None (protection.outlook.com: smtpmailserver does not designate permitted sender hosts)
The SPF record for example:
v=spf1 ip4:16X.XX.XX ip4:20X.XX.XX.X/24 ip4:10.XX.XX.X/24 ip4:19X.XX.XX.X/24 include:spf.protection.com -all
Any thoughts as to why the originating ips don't get accepted despite falling with that range?