smtp.parabolanet.com has no MX records.
Question and response
Question
dig mail.parabolanet.com. MX
Answer
The response has no answer records.
Authority
parabolanet.com. 86400 SOA ns1.parabolanet.com. root.parabolanet.com. 20181259 28800 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0