vorlon.swishmail.com has no MX records.
Question and response
Question
dig vorlon.swishmail.com. MX
Answer
The response has no answer records.
Authority
swishmail.com. 3600 SOA ns1.webgoku.com. hostmaster.swishmail.com. 2026022201 86400 3600 1209600 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0