Not sure about Evolution, but was using Thunderbird on Zen on one of my boxes a few days ago, and had no problems. What error were you getting when trying to send? Are you sure you had details correct?
Remember this, the only stupid question is the one you don't ask.
"The thing about changing the world... is that once you do it, the world's all different."
Let's share our knowledge. Otherwise, what's the point?