Basically the server ground itself to a halt a couple of days ago (I'm not certain what exactly caused it). I managed to finally connect to restart apache and mysql and the site came back up.
At the time I didn't realise that postfix (the email part of the server) had also 'stalled'. The mails were waiting on the server but not actually being delivered. I restarted postfix this morning and it started working its way through the backlog - this means that you'll probably get some notifications which you should've got a couple of days ago.
It should all be back and working properly now though