Free Postmaster Tools





Blacklist Checker

Instantly check an IP or domain against major email blacklists including Spamhaus, SURBL, SORBS, and more.

Use Blacklist Checker

SPF Analyzer

SPF is a method to prevent email sender address forgery. Enter your domain to analyze its SPF record.

Use SPF Analyzer

DMARC Wizard

Enter your domain to analyze your DMARC record or create a DMARC policy for your domain.

Use DMARC Wizard




CIDR to IP Range

Enter a CIDR notation to instantly convert it to an IP range.

Use CIDR to IP Range

IP Range to CIDR

Enter a IP range to instantly convert it to an CIDR notation.

Use IP Range to CIDR

DNS Lookup

Perform a DNS lookup against multiple widely used nameservers around the world.

Use DNS Lookup





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