srvlist.ukfast.net has no MX records.
Question and response
Question
dig srvlist.ukfast.net. MX
Answer
The response has no answer records.
Authority
srvlist.ukfast.net. 86400 SOA ns0.ukfast.net. support.ukfast.net. 2026020301 7200 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0