Cant set up mail hosting (names.co.uk)

Cant set up mail hosting (names.co.uk)

As per the title, I've successfully verified my domain name but can't seem to configure my DNS on my names.co.uk properly to sort mail hosting.  I have added both of the MX records with the host name as my domain name (jamesandrewknight.co.uk) and have set up two users (info and admin@ that domain name).  But every test email I send comes back as unsent.  Can anyone help me?  Sorry, I'm a total noob :s