mx.olly-gan.com has no CNAME records.
Question and response
Question
dig mx.olly-gan.com. NS
Answer
The response has no answer records.
Authority
olly-gan.com. 3437 SOA dns.olly-gan.com. hostmaster.olly-gan.com. 1360302891 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0