You can use the inbuilt Chat program that comes with Apple Mac OS X to connect to SureVoIP IM called Messages. It should just take a few seconds to get set up.
1. Launch Messages
2. Enter the 'Add Account' dialog.
3. Enter your SureVoIP IM credentials
a. Fill in the field 'Username:' with your SureVoIP IM username: e.g. ghenry, b. The 'Domain:' field with 'yourcompany.hosted.surevoip.co.uk', c. The 'Resource:' field can be anything you like which is used to say where you're based e.g. Office/Laptop/Phone d. The 'Password' field with your SureVoIP IM password.
4. Accept the certificate
5. Now logged in