NorthDNS
Email

Email deliverability: SPF, DKIM and DMARC

Why email lands in spam or is rejected by Gmail, and how SPF, DKIM and DMARC on NorthDNS improve delivery.

The three records

  • SPF (TXT on the domain): lists the servers allowed to send. NorthDNS uses v=spf1 mx -all.
  • DKIM (TXT on mail._domainkey): public key recipients use to verify message signatures.
  • DMARC (TXT on _dmarc): tells recipients what to do when SPF and DKIM do not align.

Configure automatically on the Email page creates all three.

Gmail rejects messages

The error 550-5.7.26 … unauthenticated means neither SPF nor DKIM validated. Make sure the domain is delegated to NorthDNS and all three records exist, then retry after propagation.

Messages in spam

  • Check the records with /dnscheck on our Discord or a tool such as mail-tester.
  • Avoid bulk sends, URL shorteners and suspicious attachments.
  • New domains have little reputation: increase volume gradually.
  • Once everything works, tighten DMARC (from p=none to p=quarantine).

Records from other providers

If you also send through another service (newsletters, CRM), add its servers to the SPF record: a domain can only have one SPF record.