dig.isi.edu has no MX records.
Question and response
Question
dig dig.isi.edu. MX
Answer
The response has no answer records.
Authority
isi.edu. 60 SOA mdrinfoblox-gm01.ads.isi.edu. hostmaster.dev.null. 2022763366 14400 1440 2419200 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0