Using wildcard subdomains in Plesk
In some situations, you may want to have domain.com as well as *.domain.com point to the same site in Plesk. Plesk will automatically set up hosting for domain.com and www.domain.com within the Apache configuration, but you can direct all subdomains for a particular domain to a certain virtual host fairly easily.
Add a CNAME or A record for *.domain.com which points to domain.com (for a CNAME), or the domain’s IP (for an A record.
Edit the /var/www/vhosts/domain.com/conf/vhost.conf or /home/httpd/vhosts/domain.com/conf/vhost.conf file and enter this information:
If the vhost.conf didn’t exist before, you will need to run:
# /usr/local/psa/admin/bin/websrvmng -av
Whether the vhost.conf was new or not, you will need to reload the Apache configuration:
# /etc/init.d/httpd reload
Credit for this fix goes to SWSoft’s KB #955