mail.servercity.co.uk has no MX records.
Question and response
Question
dig mail.servercity.co.uk. MX
Answer
The response has no answer records.
Authority
servercity.co.uk. 3600 SOA authns1.coreix.net. hostmaster.servercity.co.uk. 2015030807 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0