SD6 Email Fetch Error - Connection timeout

Hello,
We have just started to experience an issue with service desk (Build 6010) where the email fetch fails. It last imported at 10:40 am.

We have stopped the fetch, and pressing SAVE displays the error:
FAILURE :Email Settings saved successfully. But error occured while trying to check connection with mail server - Problem connecting to mailbox.

We have restarted the machine that SD lives on but this didnt resolve the issue.

The log serverout0.txt has the following entries:
[13:18:21:597]|[03-17-2008]|[SYSOUT]|[INFO]|[18]|: Exception when connecting to store.|
[13:18:21:597]|[03-17-2008]|[SYSOUT]|[INFO]|[18]|: javax.mail.MessagingException: Connect failed;
nested exception is:
java.net.ConnectException: Connection timed out: connect|

The mail is being pulled from Exchange 2003 and there are no known issues with this, all email is working fine at the moment.

Can anyone offer any advice on how to resolve this issue?

Thanks,

Matt