Over time, entries in an SPF record start piling up as new SaaS tools get added, old services get abandoned without clearing up, and then suddenly you are dealing with an SPF record that looks like a messy list. Things get worse when you add in duplicate entries, bloated ‘include’ chains, or a stray syntax error.
But the good news is that cleaning up a messed-up and bloated SPF record is not too complicated, if done correctly. This blog focuses on straightforward steps to declutter your records, tighten them up for accuracy, and give your emails the best chance of landing where they belong: in the inbox, not the spam folder.
Why do SPF records get messy over time?
Domains and organizations undergo several changes over time, and if these changes are not reflected accurately in an SPF record, it becomes messy. Here are the common reasons-
1. Multiple email service providers (marketing tools, CRMs, ticketing systems)
Organizations often use several platforms to send email: a primary mail host, a CRM for campaigns, and a helpdesk system for tickets. Each provider requires an SPF entry. Over time, this adds up, and without proper management, the record becomes crowded. The problem gets worse if you add new services without reviewing old ones, making it difficult to track which IPs or ‘include’ statements are still valid and necessary.
2. Old/unused services left behind
When businesses switch from one provider to another, old SPF entries often stay in the DNS. These unused entries serve no purpose but still count toward the lookup and length limits. They also create confusion about which senders are actually authorized. Leaving outdated records in place increases the risk of mail rejection or spoofing attempts going unnoticed, since the SPF policy does not accurately reflect the organization’s current email setup.
3. Misconfigured entries or multiple SPF records
A common mistake is publishing more than one SPF record for the same domain. SPF specifications only allow one record, so multiple entries cause a hard fail. Syntax mistakes like missing spaces, incorrect mechanisms, or invalid IP addresses also break the record. Misconfigurations can result in mail being rejected by receiving servers, even if the domain is legitimate. Regular checks are needed to avoid these issues and ensure alignment with current mail flows.
4. Overuse of ‘include’ statements leading to lookup issues
SPF allows the use of the ‘include’ mechanism to reference another domain’s SPF. While useful, each ‘include’ consumes a DNS lookup, and SPF has a strict limit of ten. If too many services are added, the record can exceed this limit, resulting in SPF validation failure. Excessive ‘include’ statements also slow down lookups and increase the chance of hitting hidden dependencies, where one ‘include’ calls another.
Step-by-step guide to cleaning up your SPF record
Cleaning up an SPF record may sound technical, but the process becomes manageable when broken into structured steps. Each step ensures your record is accurate, efficient, and within the rules defined by the SPF standard.
Step 1: Locate your existing SPF record
The first step is to identify your current SPF record. You can do this using DNS lookup tools such as MXToolbox, dig, or nslookup. These tools allow you to query your domain’s DNS TXT records and view the SPF configuration in place.
It is important to check whether you have one or multiple SPF records published. If multiple SPF records exist, that needs immediate correction since SPF only allows one record per domain.
Step 2: Remove duplicate or outdated entries
Once you have located the record, check it for duplicates or outdated entries. Some organizations mistakenly publish more than one SPF record, which automatically causes SPF validation to fail. You should also look for references to old or unused services. For example, if your company no longer uses a marketing automation platform but its entry still exists in the SPF, it should be removed. Outdated records do not add value and can increase the risk of failed checks.
Step 3: Consolidate authorized senders
The next step is to confirm which email services are currently in use. This may include platforms like Gmail, Microsoft 365, or third-party providers such as SendGrid or Amazon SES. Make a list of all active services that send mail on behalf of your domain and verify they are properly represented in your SPF record. Any provider not in active use should be removed. This ensures that only legitimate and necessary sources remain authorized to send emails.
Step 4: Optimize for DNS lookups
SPF includes a strict limit of ten DNS lookups. Every ‘include’ statement in your record adds to this count, and exceeding the limit will cause the record to fail. Review your SPF for unnecessary includes or overlapping entries. If your record is close to the limit, consider flattening it by replacing includes with the direct IP addresses of the services you use. Some organizations also use managed SPF flattening services that automate this process and keep the record updated with fewer lookups.
Step 5: Validate syntax and length
SPF is highly sensitive to formatting errors. Make sure the record begins with ‘v=spf1’ and does not contain mechanisms like ‘+all’ or ‘?all,’ which are considered insecure. Check for missing spaces, invalid IP addresses, or unsupported mechanisms. SPF strings are also limited to 255 characters per segment, so longer records must be split into multiple quoted strings. Proper syntax and adherence to length limits are critical to avoid validation failures and mail delivery issues.
Step 6: Publish the updated record
After finalizing the cleaned-up SPF record, publish it in your domain’s DNS as a TXT record. This step must be carried out carefully, as DNS updates impact all emails sent from the domain. Ensure that you replace the old record rather than adding a new one. Once published, allow time for DNS propagation, which may take several hours depending on your domain host and TTL (time-to-live) settings.
Step 7: Test your record
The last step is to test and verify the updated SPF record. Use SPF validation tools to confirm the syntax is correct and the record passes alignment checks. It is also helpful to send test emails to different mail providers to confirm that messages are accepted without delivery warnings. Continuous monitoring after changes is important, as any misconfiguration can cause disruptions in email delivery.
Best practices to keep SPF records clean
Keeping an SPF record accurate is not a one-time task. A well-maintained record requires periodic checks and adherence to some key practices that ensure ongoing reliability and security.
1. Maintain a list of authorized senders
Track every service that sends email on behalf of your domain, including mail servers, cloud providers, and third-party tools. Having a centralized list prevents accidental omissions or unnecessary additions. It also helps you identify when a provider is no longer in use so you can remove its entry from the SPF record promptly.
2. Review records quarterly or when switching providers
SPF records can quickly become outdated as organizations adopt new services or move away from existing ones. A quarterly review ensures that only active senders remain authorized. Each time you add or switch providers, verify the SPF requirements of the new service and adjust the record accordingly. Regular updates prevent the record from bloating with obsolete entries.
3. Avoid overly permissive mechanisms
Mechanisms such as ‘+all’ or ‘?all’ effectively allow any server to send on behalf of your domain, which undermines the purpose of SPF. These settings open the door to spoofing and phishing attempts because receiving servers cannot distinguish between legitimate senders and malicious ones. Instead, define authorized senders precisely and conclude the record with ‘-all’ or ‘~all’ to enforce stricter validation.
4. Combine SPF with DKIM and DMARC
SPF alone does not fully protect against spoofing or delivery issues. Implementing DKIM ensures that messages carry a cryptographic signature, while DMARC builds on both SPF and DKIM to enforce alignment and reporting. Together, these protocols provide layered protection, improve deliverability, and help prevent domain abuse. A clean SPF record is most effective when supported by DKIM and DMARC.
Conclusion
An SPF record is only effective when it is accurate, concise, and easy to maintain. Over time, records often become cluttered with unused entries, duplicate mechanisms, or unnecessary includes that push them past technical limits. Cleaning up an SPF record is about trimming away what is no longer needed, keeping only the services that actively send on your behalf, and making sure the configuration stays within the 10-lookup and length restrictions.
A streamlined SPF record improves the reliability of email delivery and ensures that your messages are correctly authenticated by receiving mail servers. It also reduces the risk of errors that could cause legitimate emails to be flagged as suspicious or rejected entirely. With regular reviews, clear documentation of authorized senders, and support from DKIM and DMARC, you can keep your domain’s email security strong and consistent.
If you have not looked at your SPF record recently, now is the right time to check. Use an SPF validation tool to see where you stand, clean up what is outdated, and confirm that the record passes alignment tests. AutoSPF makes this process easier with automated SPF flattening, monitoring, and management so your records stay optimized without the manual effort.
