Firstly, regarding backups, when the ChessPub.exe server failed I had the hard drive replaced and a sophisticated backup system put in place, with my own servers plus another outside one. I also had a lot of the code updated with the latest patches (incidentally we use Unix servers). I thought I was safe!
It turns out the backups are useless for the simple reason that the invisible Trojan horse, or whatever it was, could have infested the backups too! I know, it sounds crazy, I never knew such problems existed (well, yes I heard that the Chinese had been hacking into the Pentagon, but who would be interested in chess theory?)
I personally answered all the emails we received, either here or at improveyourchess.com, and gave the latest information from the sys admin guy (which regularly turned out to to be rather optimistic!) If anyone didn't get an answer that was either because their email didn't get through, or ours was stopped.
It never occurred to me to put a notice on the IYC site, as I couldn't imagine anyone looking there, without first emailing chesspublishing...
I have always been very careful to keep backups of the games database, but from now on I will also backup the list of subscribers...
I would like to thank all those who wrote words of support during the ordeal, about how to deal with the IT guys, and I particularly appreciated the advice to get myself a good hard drink!