Yesterday we had a sligt issue with our exchange (2000) server; In the morning everybody got a warning mail saying the drive was at 96% of the total capacity. As you can guess... 1 mail to many persons = no action :(
And then exchange could not write his logfiles anymore; and then ??? no more mail for 1500 users; Expanding the drive was not possible; Thanks to google I found this nice article 'How to Recover from "Disk Full" on an Exchange Log Drive'
Most important line from the text:
...and make sure that each database shows Log Required: 0-0 and State: Clean Shutdown.
If this is the case, the you can move all numbered log files, but do not remove the current log file (Enn.log).
Thanks again, Google :)