Learning

Finding WHOIS servers using SRV records

Every TLD registry maintains data about registered domain names. They publish this data over the WHOIS protocol. Currently, 36 registries publish the location of their WHOIS servers using SRV records. For example, the .de TLD registry publishes the location of its WHOIS server in an SRV record: ❯ dig +short _nicname._tcp.de srv 0 0 43 whois.denic.de. I’ve queried …

Finding WHOIS servers using SRV records Read More »

How to merge DMARC records

Domain-based Message Authentication, Reporting, and Conformance (DMARC) is an email authentication protocol designed to protect domains from phishing attacks and abuse by spammers. A domain may have multiple senders for different types of email, but each domain may have only one DMARC record. For example, a domain may have an on-premise Exchange server for email …

How to merge DMARC records Read More »

DMARC: A practical guide

Domain-based Message Authentication, Reporting, and Conformance (DMARC) is one of the three pillars of modern email security. DMARC works with Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) to protect against spoofing, spam, and phishing attacks. DMARC adds reporting and policy to email security: DMARC is specified in RFC 7489. How DMARC works The DMARC record for a domain …

DMARC: A practical guide Read More »

Scroll to Top