I have the following DMARC record set up:
v=DMARC1; p=none; rua=mailto:email@example.com; ruf=mailto:firstname.lastname@example.org; sp=none; fo=0:1:d:s
I have the following SPF record set up:
v=spf1 mx -all
the MX record has 3 IP addresses.
One of those IP Addresses in the MX record is used to send emails from. Majority of those emails align with DMARC well (last month, 312k emails are aligned). However, the same IP Address also shows some failure reports (700 emails failed DMARC).
When I look at the reason, it says "mail.mydomain.com" -- SPF not set.
My DMARC record is set to be in relaxed mode (emails from subdomains pass the DMARC check).
What could be the reason for those emails to fail? How can I avoid this? Should I add an SPF record under mail.mydomain.com subdomain?