$ dig ycombinator.com mx
;; ANSWER SECTION: ycombinator.com. 300 IN MX 20 alt1.aspmx.l.google.com. ycombinator.com. 300 IN MX 10 aspmx.l.google.com. ycombinator.com. 300 IN MX 20 alt2.aspmx.l.google.com. ycombinator.com. 300 IN MX 30 aspmx4.googlemail.com.
$ dig ycombinator.com mx