\newcommand{\settitle}{TITLE}
\newcommand{\setauthor}{YOU}
\newcommand{\setsubject}{SUBJECT}
\newcommand{\setlocation}{LOCATION}
\newcommand{\setmail}{mailto:place@holder.com}

\begin{filecontents*}{\jobname.xmpdata}
  \Title{\settitle}
  \Author{\setauthor}
  \Subject{\setsubject}
\end{filecontents*}
\documentclass{article}

\usepackage[T1]{fontenc} % encoding
\renewcommand{\familydefault}{\sfdefault} % sans-serif font

\usepackage[french]{babel} % langages
\frenchsetup{SmallCapsFigTabCaptions=false}

% \usepackage[ % change page dimensions
%   a4paper,
%   left=20mm,
%   top=20mm,
% ]{geometry}

% \usepackage{minted} % code integration
% \usemintedstyle{emacs}

\usepackage[a-3u]{pdfx}
\hypersetup{hidelinks} % clickable links in table of contents

\title{\settitle}
\author{\href{\setmail}{\setauthor}\\\setsubject~$\cdot$ \setlocation}
\date{}

\begin{document}
\maketitle
\flushbottom
\tableofcontents
\clearpage

\section{SECTION}
Hello, world!

\end{document}