Wait, Why Is Your SPF Failing? 🤯
You’ve set up SPF (Sender Policy Framework), added your records, and expected smooth email authentication… but instead, Google and Microsoft keep rejecting or flagging your emails as “SPF Fail” or “SPF SoftFail”.
Annoying, right? 😤
Before you start blaming the email gods, let’s break down why this happens and how to fix it—fast!
🔍 Quick SPF Health Check (Before You Panic)
First, let’s confirm your SPF record is correctly published. Run this command in your terminal:
shCopyEditnslookup -type=TXT yourdomain.com
If you don’t see a line starting with “v=spf1”, your SPF record might be missing or misconfigured.
🛠️ Common Reasons Why SPF Fails (And How to Fix Them!)
1️⃣ Too Many DNS Lookups (Google/Microsoft Reject It!)
🔴 Issue: Google and Microsoft limit SPF records to 10 DNS lookups. If your SPF includes too many external services (like SendGrid, Mailchimp, Zoho), your lookup count can exceed this limit—causing SPF to fail.
✅ Fix:
Use flattening services like
spf.toolsto optimize your SPF record.Consolidate multiple
include:statements into a single trusted relay provider.
📝 Example: Instead of this:
txtCopyEditv=spf1 include:_spf.google.com include:spf.protection.outlook.com include:sendgrid.net include:mailchimp.com -all
Try this optimized version:
txtCopyEditv=spf1 ip4:192.168.1.1 include:_spf.google.com -all
2️⃣ SPF Record Is Too Long (Exceeds 255 Characters)
🔴 Issue: Some DNS providers truncate long SPF records, breaking authentication.
✅ Fix:
Shorten your SPF record by removing unused email services.
Use subdomains for different services (e.g.,
mail.yourdomain.comfor marketing emails).
3️⃣ SPF SoftFail Instead of Pass (Google’s Strict Policies)
🔴 Issue: Your SPF policy is set to SoftFail (~all) instead of Fail (-all), allowing unauthorized senders to pass.
✅ Fix: Change your record from this:
txtCopyEditv=spf1 include:_spf.google.com ~all
To this stricter version:
txtCopyEditv=spf1 include:_spf.google.com -all
🚨 Warning: This blocks all unauthorized senders, so test it first!
4️⃣ Microsoft 365 Not Recognizing SPF? Check Your TXT Format!
🔴 Issue: Microsoft 365 can be picky about SPF syntax. If your TXT record has unnecessary spaces or characters, it might ignore it.
✅ Fix:
Make sure your SPF record is properly formatted.
Use double quotes if required by your DNS provider:
txtCopyEdit"v=spf1 include:spf.protection.outlook.com -all"
5️⃣ Emails Still Failing? SPF Alone Isn’t Enough!
Even with a perfect SPF record, email failures can still happen because:
✔️ SPF only checks the Return-Path domain (not the From address).
✔️ Google/Microsoft now recommend using DKIM and DMARC for full protection.
✅ Fix:
Set up DKIM (DomainKeys Identified Mail) for extra security.
Enforce DMARC (Domain-based Message Authentication, Reporting & Conformance) to align SPF & DKIM.
💡 Final Thoughts: SPF Fixes That Work!
If your SPF is failing for Google or Microsoft, follow these steps:
✅ Check DNS lookups (keep under 10)
✅ Shorten your SPF record (under 255 characters)
✅ Use strict SPF policies (-all instead of ~all)
✅ Ensure proper formatting for Microsoft 365
✅ Add DKIM & DMARC for extra protection
Still stuck? Need help fixing your SPF errors? Let’s chat!🚀