SPF Check online - Test SPF - SPF Records

Sender Policy Framework (SPF) is a mechanism designed to prevent email spoofing by verifying the authenticity of the sender address in an email. SPF validation is used by email servers to ensure that the IP address sending an email on behalf of the sender comes from the authorized servers.

Here is an explanation of how SPF validation works online:

1. SPF Setup:

   • The sender of an email can set up SPF for his domain by adding a special DNS record that specifies the IP addresses of the authorized servers that are allowed to send emails for that domain.

2. Receiving SPF protected email server:

   • When an email arrives from an SPF-enabled email server, the receiving server checks the SPF record of the sender's domain.

3. DNS query:

   • The receiving server performs a DNS query to obtain the SPF record of the sender domain. This record lists the IP addresses of the servers authorized to send email for the domain.

4. Sender IP Verification:

   • The receiving server compares the sending server's IP address with the authorized IP addresses listed in the SPF record.

5. SPF validation result:

   • If the IP address of the sending server matches one of the authorized IP addresses, the SPF validation is considered successful and the email is considered authentic. Otherwise, the email will be treated as potentially suspicious.

Online SPF validation tools allow users to verify the SPF configuration for a specific domain without having access to that domain's DNS configuration. These tools perform a DNS query to extract the SPF record and then display whether the sending server's IP address matches the addresses listed in the SPF record. Such online tools are useful for identifying and troubleshooting SPF configuration issues.