\documentclass[letterpaper]{article}

\usepackage[
  % grid,gridBG,
  % pscoord=false,
  % texcoord=true,
  % gridcolor=red!50,
  % subgridcolor=black!25,
  % gridunit=mm
]{eso-pic}
\usepackage[hang,flushmargin]{footmisc}
\usepackage{graphicx}
\usepackage{lipsum}

% \AddToShipoutPictureFG*{
%   \AtPageUpperLeft{
%     \put(\LenToUnit{50mm},\LenToUnit{-250mm}){
%       \includegraphics[page=1]{image}}
%   }}

\pagenumbering{gobble}
\setlength{\parindent}{0pt}
\setlength{\parskip}{1em}

\begin{document}

Sender Address \\
City, State ZIP

Month Day, Year

Recipient Name \\
Recipient Address \\
City, State ZIP

Salutation:

\lipsum[1-2]

Closing,

\vspace*{3\baselineskip}

Sender Name

Enclosures: TK

\end{document}