Why my email goes up to the page before my paper starts? [closed]

Why my email goes up to the page before my paper starts?

\documentclass{article}
%
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage{tabularx}
\usepackage{enumitem}
\usepackage{graphicx}
\usepackage{mathabx}
\usepackage{forest}
\usepackage{booktabs}
\usepackage{url}

\renewcommand{\Gamma}{\varGamma}
\renewcommand{\epsilon}{\varepsilon}
\renewcommand{\bar}{\overline}
\renewcommand{\hat}{\widehat}
\DeclareMathOperator{\Cir}{Cir}

\renewcommand{\leq}{\leqslant}
\renewcommand{\geq}{\geqslant}
\newtheorem{theorem}{Theorem}[section]
\newtheorem{definition}{Definition}[section]
\newtheorem{lemma}{Lemma}[section]
\newtheorem{example}{Example}[section]
\newtheorem{notation}{Notation}[section]
\newtheorem{corollary}{Corollary}[section]
\newtheorem{remark}[lemma]{Remark}

\newcolumntype{C}{>{\centering\arraybackslash}X}

%Extra things that are included for simplicity.

\newcommand{\Po}{\mathcal{P}}
\newcommand{\R}{\mathbb{R}}
\newcommand{\Z}{\mathbb{Z}}
\newcommand{\C}{\mathbb{C}}
%
%
\newcommand{\Sym}{\mathrm{Sym}}
\newcommand*{\Scale}[2][4]{\scalebox{#1}{$#2$}}%
\newcommand{\vt}{\mathrm{vert}}
\newcommand{\conv}{\mathrm{conv}}
\newcommand{\Fix}{\mathrm{Fix}}
\newcommand{\Span}{\mathrm{Span}}
\newcommand{\core}{\mathrm{core}}
\newcommand{\PCir }{\mathrm{PCir }}
% Used for displaying a sample figure. If possible, figure files should
% be included in EPS format.
%
% If you use the hyperref package, please uncomment the following line
% to display URLs in blue roman font according to Springer's eBook style:
% \renewcommand\UrlFont{\color{blue}\rmfamily}

\begin{document}
%
\title{Outer approximations of core points for integer programming\thanks{Supported by NSERC grant RGPIN-2015-04955}}
%
%\titlerunning{Outer approximations of core points}
% If the paper title is too long for the running head, you can set
% an abbreviated paper title here
%
\author{Naghmeh Shahverdi\and
David Bremner}

%
%\authorrunning{ David Bremner and Naghmeh Shahverdi }
% First names are abbreviated in the running head.
% If there are more than two authors, 'et al.' is used.
%
%\institute{University of New Brunswick, Fredericton, NB, E3B 5A3 , Canada \\

\email{\{ nshahver,bremner \}@unb.ca}}
%
\maketitle              % typeset the header of the contribution
%


• I can't compile this example because I get "undefined control sequence" for \email{} but my guess would be that you have your \maketitle information inside the document and not in the preamble. Usually the \maketitle is the very first thing you put in after \begin{document} and all the information it pulls is in the preamble. Or at least, that's how I have always done it. Nov 8, 2020 at 6:16
• it changes the format of title if I put makefile in the begining Nov 8, 2020 at 6:53
• Please tell us how or where \email is defined.
– Mico
Nov 8, 2020 at 8:16
• \maketitle typesets the \title, \author and \date, all as one unit. You have \email before \maketitle, so that is where it goes, before. Do xxx\maketitle yyy to make visible where the title box starts and ends. Nov 8, 2020 at 9:00
• Some document classes define \email to be included in the \maketitle. Article class does not. Nov 8, 2020 at 17:38