Let $AE(X)$ denote the Arens-Eells space on a Banach space $X$. Consider the map: $$ \begin{aligned} \delta: X & \rightarrow AE(X) \\ x&\mapsto \delta_x \end{aligned} $$ Is the map $\delta$ ever Gateau (or Fréchet) differentiable? --- Recall that $AE(X)$ is the/a [pre-dual][1] of the space $Lip_0(X)$ whose elements are Lipschitz functions sending $0\in X$ to $0\in \mathbb{R}$, $\delta_x$ denotes the evaluation map defined on Lipschitz functions $f\in Lip_0(X)$ by $$ \delta_x(f):= f(x), $$ and $AE(X)$ is normed by: $$ \|F-G\|:=\inf_{f \in Lip_0(X),\, Lip(f)\leq 1} F(f)-G(f), $$ where $Lip(f)$ denotes the Lipschitz constant. [1]: https://arxiv.org/abs/1611.01812