ok, maybe this will help, it is my mx record here at x10 (just edited a bit for privacy)
MX mysite.x10.bz. 14400 0 mysite.x10.bz.
explained a bit more from my direct admin panel/mx records:
record type : MX
name : your domain name
TTL : 14400
value : (did not select, resorted to 0) (i believe usually this is set to 10 but mines at 0)
duplicate to pointers is checked.
ive sent mail to gmail and received replies from gmail.
hope this helps and better explains it.
i should note that my domain was a free x10 domain name.
so mine works fine here.
if you have a different domain name like you.com
you would need to go to your you.com registrar
where you got the domain name to edit the mx record there.
but i believe you would add your you.com domain name.