No website? The domain name may still be in use

A browser reveals only one use

You are looking for a name for your business. Your preferred domain does not lead to a website. It is tempting to conclude that nobody uses it. Yet the name may support email, a service that does not open in your browser, or a future project.

What you observed is narrower: at that moment, with that request, you did not receive a web page. An outage or configuration problem can produce the same result.

Registration and activation are separate

DNS Luxembourg distinguishes registration of a .lu from activation through the configuration of name servers. A registered name can be inactive. The absence of a website therefore does not establish availability.

Source : DNS Luxembourg — My domain name

Move forward without assuming

Check availability through the registry’s tool or a provider. If the name is registered, assume neither that it is for sale nor that its registrant has no legitimate reason to hold it.

You can consider making contact and putting forward an offer while keeping another option open. The lack of a website reveals neither the price the registrant might request nor a willingness to sell.

If your own business uses a domain only for email, document that use. Otherwise, someone reviewing subscriptions might decide that a name “with no website” is unnecessary. Your email service deserves a decision based on more than a blank page.