My standard letter in LaTeX with the class scrlttr2 (created by a German to adhere to German letter guidelines):

\documentclass[fromalign=location, fromphone=true, fromemail=true, locfield=wide]{scrlttr2}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\setkomavar{fromname}{Max Mustermann}
\setkomavar{fromaddress}{Musterstr.\ 1\\12345 Musterstadt}
\setkomavar{fromphone}{01234/56789000}
\setkomavar{fromemail}{mustermx@provider.xy}
\setkomavar{signature}{Max Mustermann}
\setkomavar{subject}[]{}
\setkomavar{date}{7.\ August 2013}

\begin{document}
\begin{letter}{Jane Doe\\
Example street 2\\
54321 Exampleville
}
\opening{Dear Mrs.\ X,}
this is the letter I promised.
\closing{Kind regards,}
\end{letter}
\end{document}


The variables ‘from…’ set the sender, the recipient is given right after begin letter. The sender information can be set at strange places, for a very simple letter I use ‘fromalign=location’ which results in the sender information somewhere at the top right, a bit higher than the recipient, but not in the headline. With the standard settings the e-mail address is too wide for the sender field, so I widen it with ‘locfield=wide’.