web1.zixmail.net has no MX records.
Question and response
Question
dig web1.zixmail.net. MX
Answer
The response has no answer records.
Authority
zixmail.net. 600 SOA ns.zixcorp.com. noc.zixcorp.com. 2025101601 3600 300 604800 600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0