Network diagnostics and utility tools.
Check SPF records and verify if an IP is allowed to send emails.
Analyse DMARC records and check the email authentication policy.
Check the DKIM key for a domain using a selector.
Check an IPv4 address against known DNS blacklists (DNSBL).
Query DNS records (A, MX, NS, TXT) for a domain.
Check host reachability via ICMP ping.
Check if a port is reachable.
Look up domain and IP information.
Calculate the EAN13 barcode check digit.