I have 3 full web servers... I have a domain for the first domain.com, and in the DNS i have server2.domain.com and server3.domain.com with A records. domain.com has a SPF record that includes all three. Now on a domain I have hosted on server3.domain.com, some emails are being rejected and in the headers I can see a line saying SPF failed. Do I need to create a DNS Zone for the subdomains to add a SPF record? (and an A record and MX record all pointing to the subdomain?) domain.com, server2.domain.com and server3.domain.com all host different websites. Each server runs it's own services.
