ns2.umd.edu has no MX records.
Question and response
Question
dig ns2.umd.edu. MX
Answer
The response has no answer records.
Authority
umd.edu. 300 SOA blox.net.umd.edu. hostmaster.umd.edu. 2895720163 14400 3600 2419200 300
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0