webmail.mydomain.com problem and wildcard?

Hello,

I have a problem with the *.mydomain.com and webmail.mydomain.com. I have been able to swap atmail conf (see: https://www.ads-software.com/support/topic/how-to-enable-exclude-webmaildomaincom-or-mdomaincom?replies=9)

The last part of httpd/conf.d looks like

ssl.conf
webalizer.conf
welcome.conf
zz001_atmail_vhost.conf
zz001_horde_vhost.conf
zz010_psa_httpd.conf

So now i can reach webmail.mydomain.com, but the problem is every non existing subdomain points to atmail (like asdfasf.mydomain.com ) i just want to show the 404 (or something else)

How can i fix this???

regards