C #: get CNAME and MX record from domain?

Can someone tell me how to programmatically extract cname and mx records from an internet domain (www.example.com) using C #? According to my short research, I understand that this is possible using sounding a UDP socket on a DNS server, BUT, is it possible to achieve this without knowing the address of the DNS server, only a domain name, for example "www.example.com"? I think this is possible because I used some kind of third-party free toolkit to successfully record MX records without knowing the address of the DNS server.

thanks a lot