web11.serenisys.com has no MX records.
Question and response
Question
dig web11.serenisys.com. MX
Answer
The response has no answer records.
Authority
serenisys.com. 2560 SOA ns1.galaxie.cloud. hostmaster.serenisys.com. 2025101500 14400 3600 1209600 2560
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0