Yes, 200sx.org.uk can receive emails.
Yes, 200sx.org.uk seems to be a legitimate domain.
A record
109.68.33.18
MX records
ALT1.ASPMX.L.GOOGLE.COM
64.233.186.27
ALT2.ASPMX.L.GOOGLE.COM
209.85.202.27
ASPMX.L.GOOGLE.COM
209.85.201.27
ASPMX2.GOOGLEMAIL.COM
64.233.186.26
ASPMX3.GOOGLEMAIL.COM
209.85.202.27