Is it necessary to caulk between windows and the adjacent stucco exterior?

I am purchasing a home that is 5 years old. When originally made, none of the extensions (e.g. electrical outlets, pipes, etc.) that protrude from the home were sealed where these emerge from the stucco exterior. The areas around the windows were also not caulked. We have been advised that this is not necessary and may promote mildew and wood rot, not to mention unsightliness when the caulk becomes old. Conversely, we have also been told that these small "cracks" may allow water intrusion. Any thoughts on this?