Hi,
It must be some conflict with codes, share me the ftp details of website and website url, we will get it fix and will revert you, also if possible admin user/pass.
i also would like to check the google apps setting, as for UK and which hosting you may have, standard google apps setting is there or need different setting for MX records, will re check with it as well.
myself has hosted more then 200+ website at my server and have given severals google apps to my clients, so will take care of your work very professionally :)
Look forward to have long term business relationship and be your web development house.
Regards,
Prab