About Sender Policy Framework (SPF)
Policy Framework (SPF) is a set of technical standards used to prevent someone from spoofing messages on behalf of your domain by publishing a list of approved IPs, or services providers. You can enable SPF-based authentication by adding a TXT record in the domain’s DNS. This tool will check the current SPF record for your domain and determine if it is valid. In case of an issue, the tools will highlight the errors and provide possible solutions to resolve.