[[Linear Transformation|Linear]] Convergence is a category of [[Order of Convergence]] in which $\alpha=1$. Note that this does not mean the [[Series]] itself is [[Linear Transformation|Linear]], just that its [[Rate of Convergence]] is.
$\huge
\alpha\set{e^{-n}} = \lim_{ n \to \infty } \frac{\ln e^{-n-1}}{
\ln e^{-n}
}
=
\lim_{ n \to \infty }
-\frac{n+1}{n}
= \boxed{1}
$