Definition

SPF (Sender Policy Framework) is a DNS TXT record that lists which mail servers are authorized to send email on behalf of your domain — helping receivers detect spoofed messages.

Detailed Explanation

When a receiving server gets email from you@yourdomain.com, it checks DNS for an SPF record. If the sending server’s IP is not listed, the message may fail SPF authentication and land in spam.

Example record:

v=spf1 include:_spf.google.com include:servers.mcsv.net ~all
  • include: authorizes third-party senders (Google Workspace, Mailchimp)
  • ~all = soft fail for unauthorized senders
  • -all = hard fail (use when confident)

Limit: maximum 10 DNS lookups in SPF chain.

Nepal Context

Nepali businesses sending bulk email from shared cPanel hosting often fail SPF when using an ESP — fix by adding the ESP’s include to SPF, not sending marketing mail from cPanel directly.

Key Takeaways

  • One SPF TXT record per domain
  • Authorize every service that sends on your behalf
  • Verify with MXToolbox or mail-tester.com

Common Mistakes

  1. Multiple SPF records (only one allowed)
  2. Exceeding 10 DNS lookups
  3. Forgetting to update SPF when switching ESPs