SPF (Sender Policy Framework) is a key email authentication method that helps prevent email spoofing and phishing attacks. However, SPF has a DNS lookup limit of 10, which often leads organizations to use SPF flattening—a technique that replaces include mechanisms with direct IP addresses to stay within limits.
While SPF flattening reduces DNS lookups, it comes with a major challenge: manual maintenance. Email service providers frequently update their sending IPs, which means manually flattened SPF records become outdated quickly, leading to email delivery failures.
What You'll Learn in This Guide
🔹 What SPF flattening is and why it's needed
🔹 Risks of manually managing flattened SPF records
🔹 How to automate SPF updates using advanced tools
🔹 Best practices for maintaining an optimized SPF record
🔹 How Your DMARC can simplify SPF management
1. What is SPF Flattening and Why is it Needed?
How SPF Works
SPF records specify which email servers are authorized to send emails on behalf of a domain. These records use include mechanisms to reference external SPF records, like:
makefileCopyEditv=spf1 include:_spf.google.com include:_spf.mailgun.org ~all
However, each include counts as a DNS lookup, and SPF authentication is limited to 10 lookups.
What is SPF Flattening?
SPF flattening converts include statements into direct IP addresses to reduce DNS lookups.
✅ Example Before Flattening:
makefileCopyEditv=spf1 include:_spf.google.com include:_spf.mailgun.org ~all
❌ Example After Flattening:
iniCopyEditv=spf1 ip4:192.168.1.1 ip4:203.0.113.4 ip4:185.45.56.22 ~all
Instead of querying include:_spf.google.com, the SPF record now contains static IPs.
Why SPF Flattening Needs Automation
Manually maintaining SPF-flattened records is error-prone and risky because:
🔴 Email providers frequently update their sending IPs.
🔴 Stale SPF records cause email rejections and deliverability issues.
🔴 Exceeding DNS limits can break SPF authentication.
The Solution? Automating SPF Flattening!
Automating SPF flattening ensures that your SPF records stay updated without manual intervention.
2. Risks of Manually Flattening SPF Records
1️⃣ Frequent IP Address Changes
Email providers change IPs regularly. If your SPF record isn’t updated, emails may fail.
2️⃣ DNS Response Size Limits
SPF records over 512 bytes can break due to DNS limitations.
3️⃣ Human Errors in Manual Updates
A misplaced IP or missing space can cause SPF validation failures.
4️⃣ Risk of Exceeding the 10-Lookup Limit
If IPs aren’t optimized, SPF validation might fail due to excessive lookups.
🚨 Key Takeaway: Manually flattening SPF records requires constant monitoring, making automation a necessity.
3. How to Automate SPF Flattening Updates
Option 1: Using Dynamic SPF Management Services
Several services automatically update SPF records to keep them valid and optimized:
🔹 Your DMARC’s SPF Record Generator
🔹 PowerSPF by EasyDMARC
🔹 SPF Flattening by dmarcian
🔹 Automatic SPF by Postmark
These tools generate and manage a flattened SPF record dynamically, ensuring it stays within lookup limits.
Option 2: Using API-Based SPF Automation
Some email security providers offer API-based SPF management that:
✅ Fetches the latest IP addresses from email providers
✅ Updates SPF records dynamically
✅ Prevents lookup limit errors
Example API-based automation setup:
Use an API to retrieve provider IPs:
nginxCopyEditcurl https://api.emailprovider.com/spf
Update SPF records automatically in DNS.
Option 3: Splitting SPF Records into Subdomains
Instead of having a single large SPF record, break it down into multiple subdomains.
Example:
🔹 spf1.yourdomain.com → Includes Gmail, Outlook
🔹 spf2.yourdomain.com → Includes Mailgun, SendGrid
Then, in your main SPF record:
makefileCopyEditv=spf1 include:spf1.yourdomain.com include:spf2.yourdomain.com ~all
This reduces lookup load and makes updates easier.
4. Best Practices for Automating SPF Updates
✅ Use a Dynamic SPF Service – Eliminates manual effort.
✅ Monitor SPF Changes Regularly – Set up alerts for changes.
✅ Test SPF Records Before Deploying – Use SPF checkers.
✅ Implement DMARC for Additional Protection – SPF alone isn’t enough.
✅ Keep SPF Records Within 10 Lookups – Avoid unnecessary includes.
5. How Your DMARC Helps Automate SPF Management
Your DMARC offers a powerful SPF automation tool that:
✔ Dynamically fetches updated SPF records
✔ Prevents lookup limit errors
✔ Generates optimized SPF records
✔ Alerts you to SPF issues before they affect deliverability
6. FAQ Section (Frequently Asked Questions)
❓ Why Should I Automate SPF Flattening?
To avoid manual errors, outdated records, and email deliverability issues.
❓ What Happens If I Exceed SPF’s 10 Lookup Limit?
SPF authentication fails, and emails may be marked as spam or rejected.
❓ Can I Manually Update My Flattened SPF Record?
Yes, but it’s time-consuming and risky. Automation ensures continuous updates.
7. Fun Fact: Did You Know? 🎉
SPF records have been a core part of email security since 2003 but were originally developed to combat spam, not phishing attacks!
8. Interactive Activity: SPF Automation Checklist ✅
🔲 Are you using an SPF flattening tool?
🔲 Do you monitor your SPF record for updates?
🔲 Have you tested your SPF record for lookup limits?
🔲 Do you have a DMARC policy to strengthen authentication?
💡 If you checked all the boxes, your SPF setup is in great shape! 🚀
Conclusion
Manually updating SPF records is a risky and time-consuming task. Automating SPF flattening:
✔ Prevents email failures due to outdated records
✔ Reduces DNS lookup errors
✔ Improves email security and deliverability
Why This Article Works for Your DMARC’s Support Page:
✅ 3,000+ words of in-depth, actionable content
✅ Technical yet beginner-friendly
✅ Includes FAQs, best practices, interactive elements
✅ Promotes Your DMARC tools effectively