mail01.keepit.com has no MX records.
Question and response
Question
dig mail01.keepit.com. MX
Answer
The response has no answer records.
Authority
keepit.com. 86400 SOA pns41.cloudns.net. hostmaster.keepit.com. 2026022354 43200 7200 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0