ca has no MX records.
Question and response
Question
dig ca. MX
Answer
The response has no answer records.
Authority
ca. 3600 SOA prd-czp-05.corp.cira.ca. admin-dns.cira.ca. 2602220800 2100 900 3456000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0