Entering name with aligned position/address below
Leaving aside the fact that there are classes for writing letters, the job of aligning material is most easily achieved with a tabular
\documentclass[12pt,a4paper]{article}
\begin{document}
\begin{tabular}{@{}l@{ }l@{}}
To: & John Smith \\
& Position Here\\
& Address here
\end{tabular}
\end{document}
or maybe
\documentclass[12pt,a4paper]{article}
\begin{document}
To:
\begin{tabular}[t]{@{}l@{}}
John Smith \\
Position here\\
Address here
\end{tabular}
\end{document}
It's as simple as that :-)
Here shown with a \Longunderstack
:
\documentclass{article}
\usepackage[usestackEOL]{stackengine}
\begin{document}
To: \Longunderstack[l]{John Smith \\ Position Here\\ Address Here}
\end{document}