Suppose our spam and virus filters go on the blink. We quickly communicate to everyone who could experience trouble while we work on the issue. We then give frequent updates. Will this help us solve the problem faster? No, but it will provide customer service. By simply knowing what is going on, customers can pursue alternatives. They can fax documents rather than use email; they can use the telephone to create a meeting agenda. Not knowing what's going on limits their choices (and increases their frustration).
Constant updates might seem like overcommunicating to us, but our frame of reference is skewed (after all, most of us did not go into IT because we are extroverts). What feels like overcommunication to us just might be the minimum standard for quality customer service. So here's the clarion call: "Remember the airlines!"