wireless.csail.mit.edu has no MX records.
Question and response
Question
dig wireless.csail.mit.edu. MX
Answer
The response has no answer records.
Authority
wireless.csail.mit.edu. 86400 SOA auth-ns0.csail.mit.edu. bug-domain.csail.mit.edu. 2023201262 14400 300 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0