documentclass[preprint,12pt]{elsarticle}
usepackage{epsfig}
usepackage{subcaption}
captionsetup{compatibility=false}
%% The amssymb package provides various useful mathematical symbols
usepackage{amssymb}
usepackage{mathptmx}
usepackage{amsmath}
newtheorem{thm}{Theorem}
newproof{pf}{Proof}
journal{X}

begin{document}
begin{frontmatter}
title{Something as a title}
author{Someone}
ead{someone@gmail.com}
address{}

begin{abstract}
%% Text of abstract
end{abstract}

begin{keyword}
%% keywords here, in the form: keyword sep keyword
Keyword1 sep Keyword2 sep Keyword3 sep Keyword4
%% PACS codes here, in the form: PACS code sep code

%% MSC codes here, in the form: MSC code sep code
%% or MSC[2008] code sep code (2000 is the default)

end{keyword}

end{frontmatter}

%% main text
section{Introduction}
label{}
Here goes introduction of the paper

bibliographystyle{elsarticle-num}
bibliography{Bibiliography}

end{document}
endinput
%% End of file `elsarticle-template-num.tex'.

documentclass[preprint,12pt]{elsarticle}
usepackage{epsfig}
usepackage{subcaption}
captionsetup{compatibility=false}
%% The amssymb package provides various useful mathematical symbols
usepackage{amssymb}
usepackage{mathptmx}
usepackage{amsmath}
newtheorem{thm}{Theorem}
newproof{pf}{Proof}
journal{X}

begin{document}
begin{frontmatter}
title{Something as a title}
author{Abbas Karamali Ravandi}
ead{abbas_karamali@gmail.com}
address{}

begin{abstract}
%% Text of abstract
end{abstract}

begin{keyword}
%% keywords here, in the form: keyword sep keyword
Keyword1 sep Keyword2 sep Keyword3 sep Keyword4
%% PACS codes here, in the form: PACS code sep code

%% MSC codes here, in the form: MSC code sep code
%% or MSC[2008] code sep code (2000 is the default)

end{keyword}

end{frontmatter}

%% linenumbers

%% main text
section{Introduction}
label{}
 Here goes introduction of the paper

bibliographystyle{elsarticle-num}
bibliography{Bibiliography}

end{document}

defead{@ifnextchar[{@uad}{@ead}}
gdef@ead#1{bgroup%
   def_{stringunderscorecharspace}%  % <--- crucial
   def{{stringlbracecharspace}%
   def~{hashcharspace}%
   def}{stringrbracecharspace}%
   edeftmp{the@eadauthor}
   immediatewrite@auxout{stringemailauthor
     {#1}{expandafterstrip@prefixmeaningtmp}}%
  egroup
}
newcounter{ead}
gdefemailauthor#1#2{stepcounter{ead}%
      g@addto@macro@elseads{raggedright%
      letcorref@gobble
      eadseptexttt{#1} (#2)%
      defeadsep{unskip,space}}%
}

ead{abbas_karamali@gmail.com}