Posted on by Mac User

What is SPF for email and do I need it?

SPF (for mail) stands for Sender Policy Framework.

It’s an email authentication method that helps stop email spoofing—basically, it tells the world which mail servers are allowed to send email on behalf of your domain.

How it works (plain English)

  1. A domain publishes an SPF record in DNS.
  2. That record lists the servers/IPs allowed to send email for the domain.
  3. When an email is received, the recipient’s mail server:
    • Checks the SPF record
    • Verifies whether the sending server is on the approved list
  4. If it’s not allowed, the message can be marked as spam, rejected, or flagged.

What an SPF record looks like

It’s a DNS TXT record, for example:

v=spf1 ip4:192.0.2.10 include:_spf.google.com -all

Meaning:

  • v=spf1 → SPF version
  • ip4:192.0.2.10 → this IP can send mail
  • include:_spf.google.com → Google’s mail servers can send mail
  • -all → everyone else is not allowed

Why SPF matters

  • Reduces spam and phishing
  • Improves email deliverability (less going to junk)
  • Often required by major providers (Gmail, Outlook, etc.)

SPF vs DKIM vs DMARC (quick vibe check)

  • SPF → “Is this server allowed to send this email?”
  • DKIM → “Was this email altered?”
  • DMARC → “What should we do if SPF/DKIM fail?”