The problem is the company providing the service. Its CriticalPath which while being a leader in that sort of private email servicing has also seen its company screech durng the dot.com meltdown and you might have read in the business press earlier this year that several of their top execs at the time have been sent ot prison. All that mess caused a few problems and we're trying to sort it out. Expect some resolution shortly.
We're quite sorry as we rely on it also. But we know that there have been times that even Yahoo and hotMail have been down. Not acceptable, but notable.