spf3.ucdavis.edu has no MX records.
Question and response
Question
dig spf3.ucdavis.edu. MX
Answer
The response has no answer records.
Authority
ucdavis.edu. 900 SOA ns0105.secondary.cloudflare.com. netadmin.ucdavis.edu. 118867536 10800 300 2419200 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0