Technical guides for every NetTools.tech tool — what it does, how it works, how to read the results and how to troubleshoot — plus articles for system administrators, DevOps engineers and security professionals.
Tool guideEmail Tools
What goes into an SPF record, how the NetTools.tech SPF generator assembles and validates it in your browser, and how to publish and verify the result without breaking legitimate mail.
Tool guideEmail Tools
What SPF is, how receivers evaluate v=spf1 records, how the NetTools.tech SPF Lookup expands includes and counts DNS lookups, and how to fix multiple records, +all and PermError.