smtpde01.mail.net.sap has no MX records.
Question and response
Question
dig smtpde01.mail.net.sap. MX
Answer
The response has no answer records.
Authority
mail.net.sap. 300 SOA ns1.sap.net. dns.sap-ag.de. 1771254929 3505 600 3600000 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0