Improved FastCheck performance

We discovered a bug in the FastCheck code on the server side that meant folders with many unread emails would take a long time to check. This bug has now been fixed, so FastCheck users should notice faster checking times, especially in the case of folders with many unread emails.

Note that this was a server side fix, no upgrade of FastCheck is required. We do recommend that you ensure you have the latest version of FastCheck, currently 1.0.10.0, available here