mailgw.inopla.de has no MX records.
Question and response
Question
dig mailgw.inopla.de. MX
Answer
The response has no answer records.
Authority
inopla.de. 86400 SOA a.ns14.net. technik.inopla.de. 2026010611 43200 7200 1209600 86400
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0