mailgw.signicat.com has no MX records.
Question and response
Question
dig mailgw.signicat.com. MX
Answer
The response has no answer records.
Authority
signicat.com. 10 SOA ns01.osl.basefarm.net. hostmaster.basefarm.net. 2017107586 86400 3600 2419200 10
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0