There are a number of common problems that can prevent a connection to the DI-API. Here's our one minute list of quick fixes.
In some circumstances when we can’t solve problems via a support call, so we may ask to connect to your system remotely.
Users experiencing problems with Email should start by reading this FAQ which covers common issues (applies to IMAP service and hosted Exchange).
All the information you need to configure a Rackspace IMAP account from Integrated Applications.
If you wish to move your domain to Integrated Applications, there are different procedures for .uk domains and international domains.