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SPF Checker Tool

Use this tool to lookup and validate your SPF record.

SPF Record Checker

Use this tool to lookup and validate your SPF record.
Please enter a valid domain name, without http:// prefix

SPF Status

Record Checks

Valid SPF record
Failure Mode
DNS Lookups below 10 /10
Void Lookups below 2 /2
Error Details

Tags Found

Tag Value Description
v v = spf1 Record version
+ip4 Allow the listed IPv4 addresses
+ip6 Allow the listed IPv6 addresses
+include Check the SPF record of the listed domain for a matching IP address
+a Allow the IP addresses listed in the domain’s A record
+mx Allow the IP addresses of the domain’s MX hosts
+ptr Allow the IP addresses of the domain’s PTR hosts
+exist SPF passes if an A record lookup of the listed domain returns a valid result
+redirected Replace the current SPF record with that of the listed domain
-/~/? Apply a hardfail/softail/neutral result if no other mechanisms match
Any text as spf content
This is any error

spf checker

The SPF Email Authentication Protocol

SPF or Sender Policy Framework is an email authentication protocol that allows recipients to distinguish between the domain owner’s authorized list of senders, and unauthorized emails. Authenticating your email using SPF is the first step toward preventing domain name abuse and impersonation. To configure SPF you have to set up a DNS record. Pairing your SPF record with other email authentication DNS records can increase its efficacy against cyberattacks.

spf checker

What is an SPF checker?

Our SPF checker is a software tool that helps you look up and check for errors in your SPF record. SPF checks help you to verify your domain’s SPF (Sender Policy Framework) configuration. 

SPF is an email authentication protocol that enables domain owners to declare which mail servers are permitted to send emails on their domain’s behalf, hence assisting in the prevention of email spoofing and phishing.

How SPF Checker Works

An SPF checker validates a domain’s SPF record, which specifies authorized mail servers for sending emails on behalf of the domain. The SPF record checker retrieves the domain’s SPF record, parses its rules, gathers the sender’s IP address, evaluates it against the record, and determines the result as pass, fail, softfail, neutral, or SPF permerror.

Our SPF lookup tool performs the following functions:

1. Checks the existence of your published SPF record

2. Detects Multiple SPF Lookups

3. Evaluates SPF Record Validity

4. Validates IP Addresses and Domains

1. Checks the existence of your published SPF record

Our SPF check tool will evaluate whether you have an existing SPF record published on your DNS. It fetches the SPF record from the DNS of the domain you want to check and subsequently parses the contents of the SPF record to understand the rules and mechanisms defined within it. These mechanisms specify which IP addresses and mail servers are allowed to send emails on behalf of the domain.

To find the existence of your DNS record, our SPF record check tool:

Performs an SPF DNS query

The SPF checker tool starts a DNS lookup for the target domain. To query the domain’s associated DNS records, “TXT” is appended to the domain name.

Initiates SPF Record Retrieval

The DNS server will respond with the SPF record as a text (TXT) record if the domain has an SPF record. The “v=spf1” declaration is often followed by several mechanisms, qualifiers, and perhaps modifiers in an SPF record.

2. Detects Multiple SPF Lookups

Our SPF checker tool can detect the SPF lookup limit exceeding by monitoring the number of DNS queries made during the SPF record validation process. If it does, it triggers a limit exceeding warning or error.

Here’s why detecting the SPF lookup limit exceeding is useful:

Preventing SPF Record Oversights

SPF records have a default lookup limit (currently 10) to prevent excessive DNS queries during SPF record validation. Exceeding this limit can lead to incomplete SPF record processing, potentially allowing unauthorized senders to pass authentication checks. By detecting limit exceeding, our tool ensures that the SPF record is not overlooked, and all relevant mechanisms are considered.

Security and Spoofing Mitigation

Our SPF lookup tool helps ensure that SPF records are correctly configured and that all authorized sending servers are accounted for. This enhances security by reducing the risk of spoofed emails.

Compliance with Standards

The SPF record lookup tool ensures that the sending domain’s SPF record complies with this standard. Non-compliance might lead to emails being treated with suspicion or rejected by recipient servers.

Performance Optimization

By validating the DNS query limit, the tool helps optimize the performance of the email authentication process and minimizes the impact on DNS infrastructure.

Configuration Feedback

If the SPF validator tool detects a limit exceeding issue, it can provide feedback to the domain owner or administrator. This feedback can guide them in adjusting their SPF record to stay within the lookup limit

3. Evaluates SPF Record Validity

Our SPF checker tool evaluates the validity of an SPF record by checking various aspects of the record’s syntax and content.

This includes:

Validation of Character Set

The SPF record lookup tool verifies that the characters used in the SPF record fall within the permitted character set specified in the SPF standard (RFC 7208). A syntax error can be raised for any use of unsupported special characters or incorrect characters.

Length Restrictions

SPF records are limited to a maximum of 255 characters. The tool verifies that the length of the retrieved SPF record does not go over this cap. Longer records need to be shortened and may be flagged as mistakes.

Mechanism and Modifier Syntax

The tool parses the SPF record and analyses each mechanism and modifier’s syntax. It makes sure they follow the SPF record syntax standards by checking for proper usage and structure. For instance:

  • Mechanisms with the letters “a,” “mx,” “ip4”, and “include” should be formatted properly.
  • The terms “redirect” and “exp” should relate to legitimate domains.

Based on these the SPF checker tool highlights error locations so that it can be fixed swiftly and easily.

4. Validates IP Addresses and Domains

Our SPF test tool verifies that IP addresses and domain names specified within mechanisms are correctly formatted and resolved to valid destinations. For example, if an “include” mechanism points to another domain, the SPF lookup tool also verifies whether that domain has a valid SPF record.

IP Address Examination

Each IP address listed in the SPF record is examined by our SPF tester tool to make sure it is structured correctly. For IPv4 addresses, the format should be “ip4:,” and for IPv6 addresses, “ip6:2001:0db8::1.

Aligned with Domain Naming Formats

The tool ensures that domain names supplied in tags like “a,” “mx,” “include,” and “ptr” are properly formatted and adhere to domain naming conventions.

Quick Feedback on Error Fixes

To assist domain managers in fixing the SPF record, the tool may give feedback or error messages if it runs into syntax errors or problems with IP addresses or domains. This in turn ensures that the SPF record is accurately configured by the domain owner, and permitted senders are correctly authorized during the authentication process – helping improve email deliverability.