Can I use subdomains with a wildcard (*.yourdomain.com)?

No. A wildcard subdomain, where every subdomain (such as a.example.com and b.example.com) automatically points to your website, can't be used on our hosting servers. That would require the web server to be configured differently per domain, and we don't do that on a per-customer basis. Just an A record with the name * in your DNS isn't enough: a subdomain you haven't created will then show a default server page instead of your website.

What can you do instead?

• Create each subdomain you need yourself in DirectAdmin under Subdomain Management. This costs nothing extra.
• Does a subdomain need to show the same website as your main domain? Then, when creating it, choose Custom under Document Root and enter the folder of your main website, /domains/example.com/public_html.
• Do you just want to forward a subdomain to another address? Create the subdomain and set up a redirect with Site Redirection.

Detailed explanation with screenshots: Creating and deleting subdomains, A different folder for your website (document root) and Site Redirects: forwarding a domain or page in the DirectAdmin manual.