Having updated my 5.5 exchange server to 2k and running it behind an ISA server I'm getting some all port attack errors in the Apps log that point to 2 or 3 specific external mail servers from other domains. Should I worry, or is this a normal symptom of Exchange 2k behind ISA? Or though mail is coming in and out happily, web browsers who are running through the same ISA server are grinding to a halt. Strange! Tim