Purpose
SPF, DKIM, and DMARC help receiving mail servers verify whether messages are authorized and authentic.
Records
- SPF lists servers allowed to send mail for the domain.
- DKIM signs messages with a cryptographic signature.
- DMARC tells receivers what to do when SPF or DKIM alignment fails.
Best practices
Use only one SPF TXT record per domain. Start DMARC with a monitoring policy if you are unsure, then move toward stricter enforcement after reviewing mail sources.
Email troubleshooting essentials
Always separate sending problems from receiving problems. Check DNS, mailbox quota, authentication, spam filtering, mail routing, firewall blocks, and bounce messages before changing random settings.
Quick support handoff
If this article does not solve the issue, open a support ticket with the domain, service name, exact error, time the problem started, and what changed recently.
