zix.com.2.0001.arsmtp.com has no SRV records.
Question and response
Question
dig zix.com.2.0001.arsmtp.com. SRV
Answer
The response has no answer records.
Authority
0001.arsmtp.com. 600 SOA mdns1.appriver.com. support.appriver.com. 11137464 900 600 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0