Use another formula to find volume :

, k is the axis of rotation

Because the integral is (dy), the part that are being integrated is between the curve and y-axis.

First, you find the volume of the section that are bounded by y-axis and x = e, then find the volume of the section that are bounded by the curve and y-axis.

Find out which one has bigger volume then substract it with the smaller one.

Sorry, it's difficult for me to explain it with words....