Sender Policy Framework, or SPF, is a fundamental email authentication standard. It's designed to prevent email spoofing by allowing domain owners to specify which mail servers are authorized to send email on their behalf. When you send an email, the recipient's mail server checks your domain's DNS for an SPF record. If the server that sent the email is listed in that record, the email passes the check. But what happens when that record isn't there at all?
Simply put, a missing SPF record leaves your domain vulnerable and can severely impact your ability to reach the inbox. Without it, you are essentially telling the world's mail servers that you have no policy on who can send emails using your domain. This creates a major security gap and leads to significant deliverability issues.
The most immediate danger of a missing SPF record is the risk of email spoofing. Attackers can easily forge emails that appear to come from your domain. They can use this to send phishing emails to your customers, scam your employees, or distribute malware, all while using your brand's good name. Because you haven't published a policy stating who can send on your behalf, receiving servers have no simple way to reject these fraudulent emails.
Deliverability and reputation damage
Beyond the security risks, a missing SPF record is detrimental to your email deliverability. Modern email providers like Gmail and Microsoft 365 expect to see authentication records. When they receive an email from a domain without an SPF record, it's a red flag. The server has no standard way to verify the sender's legitimacy, so it's more likely to treat the email with suspicion.
This suspicion often results in one of several negative outcomes for your legitimate emails:
- Increased spam placement: Mail servers are more likely to filter your emails into the recipient's spam or junk folder.
- Outright rejection: Some servers may refuse to accept the email entirely, resulting in a bounce. You might see bounce messages mentioning the lack of an SPF record.
- Reputation damage: Over time, having your emails flagged as spam or associated with unauthenticated mail harms your domain's sending reputation, making it harder to reach the inbox even after you fix the issue.
How do you know if you have a missing SPF record?
Fortunately, checking for an SPF record is a simple process. It's a public record stored in your domain's DNS, so anyone can look it up. You don't need any special tools, just the ability to look up a TXT record for your domain.
You are specifically looking for a DNS TXT record that starts with the text v=spf1. If you check your domain's TXT records and don't find one that fits this description, then you have a missing SPF record.
Fixing a missing SPF record
Creating an SPF record is a critical step for any domain that sends email. The process involves adding a new TXT record to your domain's DNS configuration through your domain registrar or DNS provider.
This record needs to list every server, service, and third party that is authorized to send email on your domain's behalf. This includes services like Google Workspace, Microsoft 365, and any email marketing platforms you use.
Forgetting to include a sending service is a common mistake that can cause legitimate emails to fail authentication. A complete SPF record is essential. Once you have a record in place, you close a significant security loophole and take a major step toward improving your email deliverability. From there, you can build on this foundation by implementing DKIM and DMARC for comprehensive email protection.
Is a DMARC record mandatory for email sending?
Can DMARC policies be applied without an SPF or DKIM record?
What is the impact of removing a DMARC record?
What is the significance of a missing DMARC record?
Does a missing DKIM record lead to email rejection?
What SPF mechanism includes the A records of a domain?
