  Let $\Omega=\widetilde{\Omega}\setminus \overline{D}$ where
$\widetilde{\Omega}$ is a bounded domain with connected complement in $\mathbb
C^n$ (or more generally in a Stein manifold) and $D$ is relatively compact open
subset of $\widetilde{\Omega}$ with connected complement in
$\widetilde{\Omega}$. We obtain characterizations of pseudoconvexity of
$\widetilde{\Omega}$ and $D$ through the vanishing or Hausdorff property of the
Dolbeault cohomology groups on various function spaces. In particular, we show
that if the boundaries of $\widetilde{\Omega}$ and $D$ are Lipschitz and
$C^2$-smooth respectively, then both $\widetilde{\Omega}$ and $D$ are
pseudoconvex if and only if $0$ is not in the spectrum of the
$\overline\partial$-Neumann Laplacian on $(0, q)$-forms for $1\le q\le n-2$
when $n\geq 3$; or $0$ is not a limit point of the spectrum of the
$\overline\partial$-Neumannn Laplacian on $(0, 1)$-forms when $n=2$.
