mail.fiservatlanta.net has no MX records.
Question and response
Question
dig mail.fiservatlanta.net. MX
Answer
The response has no answer records.
Authority
fiservatlanta.net. 86400 SOA udns1.cscdns.net. hostmaster.cscdns.net. 2019101120 28800 7200 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0