What is SPF?
SPF (Sender Policy Framework) is a TXT record that lists which mail servers may send email for a domain. A receiving server compares the connecting IP against that list. If it does not match, the final mechanism — usually -all or ~all — decides whether to reject or mark the message.
What is DMARC?
DMARC sits on SPF and DKIM. It tells receivers what to do when a message fails authentication, and where to send aggregate reports. A domain with aligned SPF, aligned DKIM, and p=reject is far harder to spoof. Walk through a safe rollout in DMARC explained.
Build a record with the SPF generator or DMARC generator, then paste it at your DNS host and re-check here.