Due to a power failure yesterday, the fSpamlist.com server was down from approx 21:20 (GMT London) until I woke up (around 40 minutes later) and fixed the issue. Sadly it turned out the power failure had corrupted not only the file system, but the MFT and MBR. This was fixed and the server brought back online.
However, further corruption has been found in the PHP installation, preventing the sites working properly (I should've caught this when bringing it back online, but annoyingly missed it (downside of working on something when you've just woken up)). I'm working on resolving this as quickly as possible, and would like to apologise for any inconvenience.