ns4.systemlifeline.com has no MX records.
Question and response
Question
dig ns4.systemlifeline.com. MX
Answer
The response has no answer records.
Authority
systemlifeline.com. 60 SOA ns3.systemlifeline.com. jpagano.systemlifeline.com. 2026030301 3600 1800 1209600 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0