Early this morning on 27th May we learned that there is an ongoing issue with the Fasthosts email servers. This has been affecting a small number of our clients trying to connect via their webmail accounts and also their mail client accounts (Outlook, Mail etc.). We too are also being affected by this issue.
Fasthosts are fully aware of this issue and they are currently working on a solution. If you are being affected by this problem, you can keep updated by checking this blog post.
Fasthosts Issue: We are investigating a separate issue with the creation/upgrade of Exchange 2013, Mail Lite and Mail Extra mailboxes being delayed.