\documentclass[11pt]{letter}
\usepackage[margin=2.5cm]{geometry}
\signature{Dr.\ Your Name\\Your Institution}
\address{Your Name\\Department\\Institution\\email@university.edu}
\begin{document}
\begin{letter}{The Editor\\Journal Name}
\opening{Dear Editor,}

Please consider our manuscript, ``Title,'' for publication in \emph{Journal} as an Article.

% One paragraph: the question and why it matters now.

% One paragraph: what you did and the one headline finding (with a number).

% One paragraph: why this journal's readers specifically.

This work is original, not under consideration elsewhere, and all authors approved the submission. We declare no competing interests. % adjust

\closing{Sincerely,}
\end{letter}
\end{document}
