mx2.mms.t-systems-service.com has no MX records.
Question and response
Question
dig mx2.mms.t-systems-service.com. MX
Answer
The response has no answer records.
Authority
mms.t-systems-service.com. 3600 SOA ns1.mms.t-systems-service.com. secure-email.t-systems.com. 2025121101 14400 3600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0