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 Gmail and Yahoo require from bulk senders, which of those requirements the NetTools.tech compliance check can verify from DNS and one SMTP connection, and which ones need a real message or provider data.
Tool guideIP & Network Utilities
How to find the organization behind an IP address with RDAP, BGP origin data and reverse DNS, why the registered owner and the routing network can differ, and how to use the results for abuse reports and firewall decisions.
Tool guideEmail Tools
What MX records are, how sending servers use them, how to read the NetTools.tech MX lookup (priority, addresses, reverse DNS, null MX) and how to troubleshoot mail routing.
Tool guideDNS & Domains
What PTR records are, how an IPv4 or IPv6 address becomes an in-addr.arpa or ip6.arpa name, who controls reverse DNS, and why it matters for mail servers and logs.
Tool guideMy Info & Identity
How the public IP address of your connection is determined, what the registry, BGP, reverse DNS and location data around it mean, and how to troubleshoot VPN, NAT and IPv4/IPv6 surprises.
Category guideDNS & Domains
An overview of the NetTools.tech DNS and domain tools: what each one checks, which to reach for when a domain does not resolve, a change is not visible or a certificate fails, and how to combine them.