\documentclass[11pt]{article}
\usepackage{qletter}
\begin{document}

\qltoaddr{
Optional To \\
Address \\
here
}

% Include \qlnoclosing to omit automatic closing
% \qlnoclosing

\qlopening{Dear Whom,}

\qlencl{optional enclosure list}

\begin{qletter}
This is the body.
\end{qletter}

\end{document}