Reliability in Email Delivery: Why are SPF, DKIM and DMARC Mandatory?

For many businesses, business email is still the most critical communication channel. However, when it is not configured correctly, the emails you send end up in the spam folder or are rejected. The key to preventing that is the SPF, DKIM and DMARC records.

SPF (Sender Policy Framework)

It specifies which IP addresses are authorized to send email for your domain. The receiving server uses this record to verify that an incoming email comes from an authorized source.

Example record:

v=spf1 a mx include:_spf.fiberserver.net.tr ~all

DKIM (DomainKeys Identified Mail)

It signs the email digitally and gives the recipient the assurance that “this email was really sent from this domain and was not altered on the way”. The signature is created with a private key on the mail server, and the recipient verifies it with the public key in DNS.

DMARC (Domain-based Message Authentication, Reporting and Conformance)

It combines the SPF and DKIM results and decides what to do with emails that fail verification: do nothing, quarantine, or reject. It also sends you reports so you can see whether your domain is being abused.

Example record:

v=DMARC1; p=quarantine; rua=mailto:[email protected]

Conclusion

Configuring these three records correctly directly affects your sending reputation and delivery rate. After adding the records, send a test email and check the result; the safest approach is to start DMARC in monitoring mode, review the reports, and tighten the policy afterwards.

At FiberServer, all of our email services support SPF, DKIM and DMARC, and during setup we can define these records correctly on your behalf.