Once you create an SPF record and publish it on your domain’s DNS, your job is not done. SPF requires constant adjustment, especially if multiple employees and vendors send emails on your behalf. Moreover, there are a few restrictions imposed on SPF usage. If you don’t stay on top of them, your email authentication can take a hit, allowing spoofing and phishing emails to bypass security protocols.
Incorrect or outdated SPF records are gold mines for threat actors. So, for example, if you once used a marketing platform or mail server and forgot to remove it from your SPF, they can spoof emails through that old path and make them look legitimate.
Common issues that arise after SPF setup
Several issues arise after setting up an SPF record. Here are the challenges you can face when maintaining it over time.
Exceeding the 10 DNS lookup limit
SPF has a hard cap of 10 DNS lookups. Every ‘include mechanism, redirect, or reference to an external domain counts toward this limit. If you exceed it, your SPF record will automatically fail, and legitimate emails may get flagged as suspicious or even blocked. This usually happens when businesses rely on multiple third-party platforms, like marketing tools, CRMs, or cloud mail providers, without consolidating or optimizing their SPF entries.
Missing new third-party email senders
Your SPF record is accurate only if it has the latest list of services. If your company starts using a new bulk mailer, ticketing tool, or customer engagement platform but forgets to add it to SPF, emails sent from that service will fail authentication. Such emails either land in the spam folder or bounce back.
As a result of this, customers never see your campaigns, and your efforts and budgets go to complete waste. This is why regular audits and an updated inventory of all email sources are critical.
Incorrect syntax or formatting errors
It’s easy to overlook small mistakes in SPF syntax, like misplaced colons, extra spaces, or forgetting the ‘-all’ mechanism at the end. Even a single typo can break the entire record. DNS systems may not always flag the issue immediately, but mail servers typically will. These errors not only cause failed authentications but can also confuse spam filters, leading to unpredictable delivery problems.
How to regularly maintain your SPF record?
Here is the aftercare required for an SPF record to ward off spoofing and phishing attempts.
Keep an inventory of all authorized email sources
The biggest thing in SPF maintenance is visibility. This means that you must know exactly which services and mail servers are sending emails on behalf of your domain. This includes your primary mail server, cloud providers such as Microsoft 365 or Google Workspace, and third-party platforms, including marketing automation tools, CRM systems, and helpdesk software. Without an updated inventory, it’s easy to miss entries, which can lead to authentication failures. Maintaining a simple spreadsheet or using an email security dashboard can help track all current senders in one place.
Update SPF records when adding new services like CRM and marketing tools
Every time you bring in a new service that sends mail under your domain, you must update your SPF record accordingly. For example, if your marketing team adopts HubSpot or Mailchimp, or your sales team starts using a CRM with built-in email functionality, those servers need to be explicitly authorized in your SPF.
Failing to complete this step means emails from the new tool will likely end up in spam or be rejected outright. Setting up a process where IT or security teams are notified before a new service is onboarded can prevent these gaps.
Remove unused or outdated IPs and domains
Over time, many services get retired or you may switch to different vendors. If you don’t clean up the old entries in your SPF record, you are exposing your domain to cyber abuse. Attackers look for such ‘orphaned’ entries to impersonate your brand, as your SPF record still technically permits emails sent from them. That’s why it’s important that you regularly audit your SPF record and remove any IPs or domains that are not in use anymore. This helps maintain a lean, accurate, and less exploitable SPF record.
Test your SPF record after every change
Finally, you should not make any changes without testing. Even a minor syntax mistake can make your record erroneous, ruining your email authentication setup completely. Use free SPF validation tools to confirm your record is valid after every update. You should also run email tests to make sure messages are being delivered as expected. Beyond manual checks, consider setting up automated monitoring that alerts you if your SPF record becomes invalid or if new authentication failures appear.
If you need our help in doing all this for you, then reach out to us today.
