Está configurado corretamente de uma perspectiva de DNS:
dmourati @ cm: ~ $ dig -t mx sfr.continuumconcepts.com
; <<>> DiG 9.3.4-P1.2 <<>> -t mx sfr.continuumconcepts.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31579
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 3
;; QUESTION SECTION:
;sfr.continuumconcepts.com. IN MX
;; ANSWER SECTION:
sfr.continuumconcepts.com. 900 IN MX 10 sfr.continuumconcepts.com.
;; AUTHORITY SECTION:
continuumconcepts.com. 897 IN NS ns46.domaincontrol.com.
continuumconcepts.com. 897 IN NS ns45.domaincontrol.com.
;; ADDITIONAL SECTION:
sfr.continuumconcepts.com. 897 IN A 184.168.71.236
ns45.domaincontrol.com. 718 IN A 216.69.185.23
ns46.domaincontrol.com. 718 IN A 208.109.255.23
Você ainda não tem um ouvinte SMTP nesse host:
dmourati @ cm: ~ $ telnet sfr.continuumconcepts.com. 25
Tentando 184.168.71.236 ..