What is an SPF policy tester, and why does it matter?
Sender Policy Framework (SPF) is an email authentication protocol that prevents unauthorized sources from sending emails on behalf of a domain. SPF works by specifying which IP addresses are allowed to send messages from a domain using a DNS record.
An SPF policy tester is a tool that checks and validates these IP addresses. It ensures that the addresses are correctly configured, helping to ensure the record is valid and senders are authorized.
Tip: Ensure email sources are added correctly, as misconfigured or missing senders can cause email delivery failures.
How SPF works: A simple explanation
SPF works by verifying the sending server’s IP address against the list of authorized addresses specified in the domain’s SPF record. If the IP address matches an entry in the SPF record, the email passes the SPF check. If not, the email might be rejected or flagged as suspicious.
An SPF record is a DNS TXT record containing mechanisms and qualifiers that define which servers are authorized to send emails on behalf of a domain. For example:
| Host | Type | Value |
|---|---|---|
| @ | TXT | v=spf1 ip4:192.168.0.1 -all |
v=spf1indicates the SPF versionip4specifies authorizedIPv4addresses-allinstructs servers to reject emails sent from any address that isn’t listed
This configuration helps receiving email servers determine whether an incoming message is sent from an authorized source.
Why you should use an SPF policy tester
Performing an SPF record check helps ensure the protocol is correctly configured. An accurate record assists your business by:
- Preventing email spoofing and phishing attacks that can harm brand reputation
- Improving successful email delivery and reducing the chance of messages being flagged as Spam
- Identifying and fixing common misconfigurations, such as unlisted sources
Misconfigured SPF records can result in failed email delivery or allow cybercriminals to impersonate a domain, posing risks to a company’s security and communication reliability.
Benefits of using an SPF policy tester
An SPF policy tester offers the following advantages:
- Validation of SPF syntax and structure to ensure compliance with SPF standards
- Error detection that highlights issues that could affect email delivery
- Insight into the DNS lookup number, which can invalidate a record (if the limit is exceeded)
- Improved confidence in email authentication by confirming correct SPF implementation
How to use the SPF policy tester tool
To use our SPF policy tester:
- Enter the email and IP address in the SPF policy tester input fields
- The tool checks the SPF record in the DNS
- It validates the address
- Details are provided, explaining the SPF policy
Best practices for SPF records
To maintain valid and effective SPF records, follow these best practices:
- Include all third-party senders (such as email marketing platforms) using the
includemechanism - Avoid exceeding the 10 DNS lookup limit, which can cause SPF failures
- Use a single SPF TXT record per domain to prevent conflicts
- Keep SPF records updated as your organization’s email infrastructure changes
- Avoid using deprecated mechanisms such as
PTR, which can create reliability issues - Always publish SPF records as TXT in the DNS settings
Try our SPF policy tester tool now
Protect your business’s domain and improve email deliverability with a properly configured SPF record. Ensure your company’s SPF record is valid with Sendmarc’s easy-to-use SPF policy tester.
Complete a free test now and take the first step toward stronger email authentication and security. Perform an SPF record check now.
Interested in full email protection? Sign up for Sendmarc’s email security solutions for advanced SPF management, Domain-based Message Authentication, Reporting, and Conformance (DMARC) enforcement, and continuous domain monitoring.