Wildcard DNS record / any subdomain resolve one IP (wilcard)

A wildcard DNS record in a zone file looks similar to this example:

MX                                  IN   A       192.168.50.1
mail                                 IN   A        192.168.50.2

*.tayab.com.    IN   CNAME mail.tayab.com.
(this will be  anyname.tayab.com  refer to IP 192.168.50.2)

or

*.tayab.com.   3600 IN  MX 10 mx.tayab.com.


This wildcard DNS record will cause DNS lookups on domain names ending in tayab.com that
do not exist to have MX records synthesized for them.
So, any lookup for the MX record for somerandomname.tayab.com would return an MX record pointing to mx.tayab.com.