Why It Matters
Missing or misconfigured email authentication records cause legitimate business emails to be flagged as spam or rejected by inbox providers (Google, Microsoft), damaging domain sender reputation.
MX Records: Point MX records accurately to your active email provider servers (Google Workspace, Microsoft 365).
SPF Record (TXT): Define authorized sending IP addresses (e.g., v=spf1 include:_spf.google.com ~all).
DKIM Key (TXT): Embed public DKIM cryptographic key records matching signed outbound mail headers.
DMARC Policy (TXT): Start with a monitoring policy and a reporting address (v=DMARC1; p=none; rua=mailto:[email protected]). Once the reports show that all your legitimate senders (your email provider, newsletter tool, CRM, invoicing software) pass, move to p=quarantine and then p=reject.
Monitor DMARC Reports: Review aggregate DMARC reports regularly to identify unauthorized sending services attempting to spoof your domain name.
Bulk Sender Requirements
Since 2024, Google and Yahoo require anyone sending large volumes of email to their users to have SPF, DKIM and a DMARC record, plus one-click unsubscribe for marketing email. Even small senders get better inbox placement with all three in place.