How to Fix SPF Record Errors — Step-by-Step Guide (2025)

Published on November 6 2025 • by MailTested Team

Sender Policy Framework (SPF) is the first line of defense against spoofed emails. But when the record is misconfigured — duplicated, malformed, or exceeds DNS limits — your legitimate messages fail authentication and land in spam. This guide explains how to diagnose and fix every common SPF error so your domain passes validation every time.

1️⃣ Understand What an SPF Record Does

An SPF record tells receiving servers which mail hosts are authorized to send on behalf of your domain. It’s a simple TXT line in DNS that begins with v=spf1 and ends with a qualifier like ~all or -all.

v=spf1 include:_spf.google.com include:mail.yourserver.com -all

If this single line is broken — or you have more than one — authentication fails. Mailbox providers like Gmail, Outlook, and Apple Mail will either soft-fail or reject the message outright.

Run SPF Record Check →

2. Common SPF Record Errors

The majority of SPF failures fall into five categories:

Duplicate SPF Records — only one SPF TXT record is allowed per domain.
Syntax Errors — missing spaces, stray quotes, or typos like spf=1 instead of v=spf1.
Too Many DNS Lookups — SPF is limited to 10 DNS mechanisms and modifiers.
Missing Includes — forgetting to add include: for services that send on your behalf.
Incorrect “All” Qualifier — using ?all or +all weakens your record and invites spoofing.

Each of these issues reduces the trust score of your domain. Even if the message is accepted, it may go straight to spam because the SPF check fails silently.

3. How to Fix Each SPF Error

Duplicate SPF Records

Delete all but one SPF TXT record. Combine the contents into a single valid line using multiple include: statements.

Syntax Mistakes

Remove quotation marks, verify spaces between mechanisms, and ensure it starts with v=spf1. You can copy-paste the final version into MailTested’s SPF Checker to confirm syntax before publishing.

Too Many DNS Lookups

SPF allows only 10 lookups (include, a, mx, ptr, exists, redirect, etc.). If you exceed this, servers return “PermError: too many DNS lookups.” Flatten unnecessary includes or use sub-records provided by your provider.

Missing Includes or Hosts

Every sending source (Google Workspace, Microsoft 365, transactional SMTP, etc.) must be listed. Find their official SPF entry and append it:

v=spf1 include:_spf.google.com include:spf.sendgrid.net -all

Incorrect “All” Mechanism

Use ~all for soft fail or -all for strict fail. Avoid ?all or +all — they effectively disable SPF protection.

4. SPF Best Practices (2025)

Only one SPF record per domain
Keep lookups ≤ 10 to prevent PermError
Always end with ~all or -all
Use a dedicated sending subdomain for marketing mail
Re-test after each DNS change

5. Validate & Monitor with MailTested

After updating your DNS, propagation can take up to a few hours. Then send a test email to MailTested — our system checks your SPF, DKIM, and DMARC alignment, verifies lookup counts, and flags any hidden syntax problems before they affect deliverability.

Run Full Deliverability Test →

✅ Conclusion

Fixing SPF errors is not rocket science — it’s precision. A clean record improves authentication score, protects your domain from spoofing, and keeps your emails in the inbox. Test your domain regularly on MailTested and stay ahead of provider policy changes.