Zacco explains … defensive domains

18 September 2025

Defensive domains, parked domains – what do they have to do with domain security and brand reputation? Zacco’s domain name security expert Victor Schönemann has taken some minutes to talk to us and shed some light on the topic.

Hi there, Victor! What are defensive domains?

These are domain names similar to your own that you register to prevent brand abuse. For example they would typically contain typos, different extensions like .org, or hyphens.

Why should you have them?

To avoid customer confusion and to prevent attackers from using look-alike domains to launch phishing attacks, scam your customers, and tarnish your brand’s reputation. They should be part of any proactive brand protection strategy.

How do you protect them and turn them into valuable brand assets?

Simply owning defensive domains isn’t enough as an unprotected domain can be used to send fake emails that look legitimate. You must secure them to protect your brand’s reputation. Our general advice would be to configure email authentication including:

• SPF (Sender Policy Framework):
  Create an SPF record that explicitly states that this domain should not send emails.
• DKIM (DomainKeys Identified Mail):
  Since no emails are sent, a DKIM record isn’t strictly necessary for outgoing mail, but having a policy is best practice.
• DMARC (Domain-based Message Authentication, Reporting & Conformance):
  This is the key. A strict DMARC policy (p=reject) tells receiving email servers to block any email that claims to be from your defensive domain. It’s your enforcement arm.

So, last question, do you recommend clients to register defensive domains?

Yes, 100%. You can’t protect something you don’t own. However, simply registering (defensive) domains is only half the job. True brand protection means closing every backdoor, and that requires fully securing each domain in the portfolio to turn it from a potential liability into a genuine security asset.

I and the Digital Brand team assist our clients with their domain name matters on a daily basis, often in collaboration with Zacco’s trademark attorneys. Our approach acknowledges and values domains as the digital extension of a brand, recognising that they are an integral part of our clients’ IP portfolio and vital for the success of a business.