_spf3.mchsi.com has no MX records.
Question and response
Question
dig _spf3.mchsi.com. MX
Answer
The response has no answer records.
Authority
mchsi.com. 300 SOA pdns104.ultradns.com. internetsupport.mediacomcc.com. 2021073138 10800 3600 1209600 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0