Paul, I want to know, when memory of your server gets full, how shall we contact you? Or is it even Possible?
If you PM me here then I usually get an e-mail within at least 5 minutes. That's the best way.
When /servermem shows a second number consistently near 98% or 99% (it will fluctuate sometimes)... and especially if you see a lot of "null" users logged in when doing /who (and the memory is high)... then PM me here.