How to Avoid the SPF Lookup Limit?
Your SPF record might look perfectly fine on the surface, but it could still be quietly hurting your email deliverability. One of the most common reasons is hitting the SPF lookup limit. When your SPF record crosses the allowed 10 DNS lookups, it becomes invalid in the eyes of receiving servers. If your SPF record goes over this limit, servers may stop trusting your emails, and your emails can go to spam or get blocked.
This usually happens as your setup grows. Every new email tool, marketing platform, or third-party service adds more entries to your SPF record, increasing the number of DNS checks required. Before you know it, you've exceeded the limit without even realizing it.
In this guide, we'll break down SPF limitations, explain why this limit exists, and show you how to fix and avoid these errors before they start affecting your domain reputation. If you are new to the topic, start with our guide on what an SPF record is.
What is the SPF Lookup Limit and Why Does it Exist
The SPF lookup limit is a rule that allows only 10 DNS lookups during an SPF check. In simple words, when a mail server checks your SPF record, it can only do up to 10 DNS checks to verify your email. This is also called the SPF DNS lookup limit.
These lookups occur when your SPF record uses include, a, mx, ptr, or redirect. Each of these can add one or more DNS checks. Even if your record looks short, some includes can add more lookups in the background.
If your SPF record goes over this limit, the check fails with a PermError (too many DNS lookups). After that, the server may stop trusting your SPF record and treat your email as unsafe.
This limit exists for two primary reasons:
Protects DNS Servers and Prevents Overload
Every SPF check requires DNS queries, and each query consumes server resources such as bandwidth, memory, and processing power. If there were no limit, a single SPF record could trigger dozens (or even hundreds) of lookups. This would put heavy pressure on the DNS infrastructure, making it slower or unstable for everyone using it.
Keeps Email Delivery Fast and Prevents Misuse
Each DNS lookup takes time. More lookups mean slower email verification, which can delay or even fail message delivery. The limit ensures emails are checked quickly. It also helps stop abuse, where attackers could create complex or looping SPF records to overload systems or cause disruptions.
What Happens When You Exceed the SPF Limit
When you exceed the SPF lookup limit, your SPF check fails completely. This can cause several problems that affect your email delivery and your domain's reputation.
SPF Check Fails with PermError
Once your SPF record crosses the allowed lookup limit, it returns a PermError (permanent error). This means the receiving server cannot properly verify your SPF record. As a result, your email fails authentication, even if your sending sources are actually legitimate.
Emails Land in Spam
When SPF fails, email providers lose trust in your domain. Since SPF is a key authentication method, failing it makes your emails look suspicious. Because of this, your emails are more likely to be filtered into spam folders instead of reaching the inbox.
Emails May Get Blocked
In stricter environments, especially corporate or secure mail systems, failed SPF checks can lead to outright rejection. This means your emails won't be delivered at all. They can get blocked before even reaching the recipient's mailbox.
Damage to Domain Reputation
Repeated SPF failures can hurt your domain's reputation over time. Mailbox providers may start flagging your domain as unreliable or risky. This can impact not just one campaign, but all future emails you send from that domain.
Common Reasons You Hit the SPF Lookup Limit
Here's why things usually go wrong and you end up crossing the SPF record DNS lookup limit:
Too Many "include" Statements
Each include in your SPF record tells the receiving server to fetch another domain's SPF record, which triggers a DNS lookup. When your setup depends on several email service providers, each one adds its own include entry. These lookups quickly add up and can exceed the SPF lookup limit, causing your SPF check to fail with a PermError.
Nested "include" Entries
An include does not always mean just one lookup. The included domain can have its own SPF record with additional include entries. This creates a chain of DNS queries. So even if your SPF record looks small, these hidden or nested includes can silently push you over the permitted number.
Old or Unused Services
Over time, you may stop using certain email tools but forget to remove them from your SPF record. These unused include instances still trigger DNS lookups during SPF checks. Even though they serve no purpose, they count toward the limit and increase the chances of exceeding the allowed number of lookups.
How to Fix the SPF Record Limit Issue
If you've hit the SPF record DNS lookup limit, don't worry — there are practical ways to fix it and stay within the allowed range. The goal is simple: reduce the number of DNS lookups without breaking your email setup. This is how you can proceed:
Remove Unnecessary "include" Statements
Each include adds a DNS lookup, and nested ones can increase this count even more. Review your SPF record and remove services you no longer use. You can also replace some include entries with ip4 or ip6 mechanisms, which don't trigger DNS queries and help reduce your overall SPF limit.
Replace "includes" with IP Addresses
Where possible, use ip4 and ip6 instead of includes. These define allowed sending IPs directly, avoiding extra lookups. This is especially useful if you rely on a few stable email sources and want to stay within SPF limitations.
Remove Duplicate or Linked Domains
Sometimes, one included domain already references another. Keeping both creates unnecessary lookups. Cleaning these overlaps helps reduce your lookup count and keeps your SPF record efficient.
Delete PTR and Invalid Entries
The ptr mechanism can trigger multiple DNS queries and is not recommended. Also, remove any invalid or unused domains that no longer send emails on your behalf. These add to your lookup count without any benefit.
Use EasyDMARC Tools for a Smarter Fix
Instead of manually fixing everything, you can use EasyDMARC's SPF Lookup Tool to check how many lookups your record is using and detect hidden issues.
For a long-term solution, EasySPF by EasyDMARC is a much better option. It lets you manage all your sending sources through a single include, so you don't have to worry about exceeding the SPF DNS lookup limit. Plus, it updates automatically — no manual fixes needed.
Keep your record simple as you grow
Most SPF lookup-limit problems come from records that grew over time. Whenever you add or remove an email service, re-check your record and prefer ip4/ip6 over extra include entries where you can. If you also manage authentication end to end, see our guides on SPF soft fail vs hard fail and multiple SPF records.
Frequently Asked Questions
How often should I check my SPF record?
You should check your SPF record every time you add or remove an email service. Even small changes can increase DNS lookups. A quick monthly check also helps catch hidden issues before they impact deliverability or cause SPF errors.
Does SPF alone guarantee email deliverability?
No, SPF alone is not enough. It only verifies sending sources. For better results, you should also use DKIM and DMARC. Together, they improve trust, protect against spoofing, and increase your chances of landing in the inbox.
Can subdomains help manage SPF better?
Yes, using subdomains can help distribute SPF records. Instead of putting all services in one record, you can assign different tools to different subdomains. This reduces lookup pressure on your main domain and helps you stay within limits.
What is the safest long-term way to manage SPF records?
The safest way is to simplify and automate your SPF setup. Tools that manage includes and updates for you reduce manual errors. This helps you stay within limits, avoid misconfigurations, and maintain stable email deliverability over time.