\makeatletter
% Variables in Alphanumeric Order
\def\@LetterEnclosureBody               {}
\def\@LetterEnclosureList               {}
\def\@LetterEnclosureTitle              {}
\def\@LetterAfter                       {}
\def\@LetterBefore                      {}
\def\@LetterClosing                     {}
\def\@LetterConfigurations              {}
\def\@LetterContent                     {}
\def\@LetterCopies                      {}
\def\@LetterDate                        {}
\def\@LetterOpening                     {}
\def\@LetterReceiverCountry             {}
\def\@LetterReceiverFirstName           {}
\def\@LetterReceiverInstituteLong       {}
\def\@LetterReceiverInstituteShort      {}
\def\@LetterReceiverLastName            {}
\def\@LetterReceiverMunicipality        {}
\def\@LetterReceiverPostalCode          {}
\def\@LetterReceiverStreet              {}
\def\@LetterReceiverStreetExtra         {}
\def\@LetterReceiverStreetNumber        {}
\def\@LetterReceiverTitle               {}
\def\@LetterSenderCountry               {}
\def\@LetterSenderEMail                 {}
\def\@LetterSenderFax                   {}
\def\@LetterSenderFirstName             {}
\def\@LetterSenderHomepage              {}
\def\@LetterSenderKey                   {}
\def\@LetterSenderLastName              {}
\def\@LetterSenderLogo                  {}
\def\@LetterSenderMobile                {}
\def\@LetterSenderMunicipality          {}
\def\@LetterSenderNickName              {}
\def\@LetterSenderPostalCode            {}
\def\@LetterSenderStreet                {}
\def\@LetterSenderStreetExtra           {}
\def\@LetterSenderStreetNumber          {}
\def\@LetterSenderTelephone             {}
\def\@LetterSenderTitle                 {}
\def\@LetterSignature                   {}
\def\@LetterSubject                     {}
\def\@LetterStyle                       {}
\def\@LetterType                        {}

% Frontend
\newcommand{\makeLetter                 }[1]
{
  % load letter style
  \@for\tmp:=\@LetterStyle\do           {\input{\source/styles/letter/\tmp.tex}}

  \constPDF
    {\@LetterSenderFirstName\ \@LetterSenderLastName}
    {\@LetterSubject vom \@LetterDate}
    {\@LetterType}
    {}
    {}
    {}

  % Positons, Lengths, Alingments, etc.
  \MSonehalfspacing
  \newgeometry
  {
    textwidth = 16.5cm,
    left      = 2.5cm,
  }
  \@setplength{lochpos}{1.0cm}
  \@setplength{locwidth}{7.5cm}
  \newlength{\@signatureHeight}
  \newlength{\@signaturePadding}
  \newlength{\@signatureBefore}
  \setlength{\@signatureHeight}{1.2cm}
  \setlength{\@signaturePadding}{.3\normalbaselineskip}
  \setlength{\@signatureBefore}{\@signatureHeight+\normalbaselineskip}

  % Input Variables are set now, lets use them
  % set pdf metadata
  \KOMAoptions
  {
    foldmarks = H,
    subject   = titled,
  }
  \setkomavar{backaddress}
  {
    \@LetterSenderFirstName\ \@LetterSenderLastName\\
    \@LetterSenderStreet~\@LetterSenderStreetNumber\\
    \ifnotempty{\@LetterSenderStreetExtra}{\@LetterSenderStreetExtra\\}
    \ifnotempty{\@LetterSenderCountry\,}\@LetterSenderPostalCode~\@LetterSenderMunicipality
  }
  \setkomavar{backaddressseparator}     {\,·\,}
  \setkomavar{date}                     {\@LetterDate}
  \setkomavar{location}
  {{
    \scriptsize
    \ifthenelse{\equal{}{\@LetterSenderStreetExtra}}
      {\def\@fromExtra{}}
      {\def\@fromExtra{\multicolumn{3}{l}{\@LetterSenderStreetExtra}\\}}
    \begin{tabular}{r@{}ll}
      \multicolumn{3}{l}{\@LetterSenderFirstName\ \@LetterSenderLastName}                                         \\
      \multicolumn{3}{l}{\@LetterSenderStreet~\@LetterSenderStreetNumber}                                         \\
      \@fromExtra
      \multicolumn{3}{l}{\ifnotempty{\@LetterSenderCountry\,}\@LetterSenderPostalCode~\@LetterSenderMunicipality} \\
      \ifnotempty{\@LetterSenderTelephone}  {\phoneicon\,     & \IfLanguageName{ngerman}{Telefon}{Telephone}:   & \@LetterSenderTelephone               \\}
      \ifnotempty{\@LetterSenderFax}        {\faxicon\,       & \IfLanguageName{ngerman}{Fax}{Telefax}:         & \@LetterSenderFax                     \\}
      \ifnotempty{\@LetterSenderMobile}     {\mobileicon\,    & \IfLanguageName{ngerman}{Mobil}{Mobile Phone}:  & \@LetterSenderMobile                  \\}
      \ifnotempty{\@LetterSenderEMail}      {\emailicon\,     & E-Mail:                                         & \emaillink{\@LetterSenderEMail}       \\}
      \ifnotempty{\@LetterSenderKey}        {\keyicon\,       & PGP:                                            & \httpslink{\@LetterSenderKey}         \\}
      \ifnotempty{\@LetterSenderHomepage}   {\homepageicon\,  & Homepage:                                       & \httpslink{\@LetterSenderHomepage}    \\}
    \end{tabular}
  }}
  \ifnotempty{\@LetterSenderLogo}
    {
      \KOMAoptions{fromlogo=true}
      \setkomavar{fromlogo}             {\includegraphics[width=0.23\linewidth]{\@LetterSenderLogo}}
    }
  \setkomavar{place}                    {\@LetterSenderMunicipality}
  \setkomavar{signature}
  {
    \ifnotempty{\@LetterSignature}
      {
        \\[-\@signatureBefore]
        \includegraphics[height=\@signatureHeight]{\@LetterSignature}\\[-\@signaturePadding]
      }
    \@LetterSenderFirstName~\@LetterSenderLastName
  }
  \setkomavar{subject}                  []{\@LetterSubject}

  % set default values of variables of other modules
  \@ResumeFromLetter

  % some custom configuration, might override defaults
  \@LetterConfigurations

  \begin{document}
    % cover letter
    \noWordBreaks
    \addsectiontocentry{}{Anschreiben}
    \def\@institute                     {}
    \ifnotempty{\@LetterReceiverInstituteLong}
      {\def\@institute                  {\@LetterReceiverInstituteLong\\}}
    \def\@lastName                      {}
    \ifnotempty{\@LetterReceiverLastName}
      {\def\@lastName                   { \@LetterReceiverLastName}}
    \def\@streetExtra                   {}
    \ifnotempty{\@LetterReceiverStreetExtra}
      {\def\@streetExtra                {\@LetterReceiverStreetExtra\\}}
    \def\@country                       {}
    \ifnotempty{\@LetterReceiverCountry}
      {\def\@country                    {\@LetterReceiverCountry\,}}
    \begin{letter}
      {
        \@institute
        \@LetterReceiverFirstName\@lastName\\
        \@LetterReceiverStreet~\@LetterReceiverStreetNumber\\
        \@streetExtra
        \@country\@LetterReceiverPostalCode~\@LetterReceiverMunicipality
      }
      \@LetterBefore
      \opening{\@LetterOpening\IfLanguageName{ngerman}{,}{.}}
      \@LetterContent\par
      \closing{\@LetterClosing}
      \vfill
      \ifnotempty{\@LetterEnclosureList}
        {
          \setkomavar*{enclseparator}{\@LetterEnclosureTitle}
          \encl{\@LetterEnclosureList}
        }
      \ifnotempty{\@LetterCopies}
        {
          \cc{\@LetterCopies}
        }
      \@LetterAfter
    \end{letter}

    % main matter
    #1

    % enclosure, e.g. documents
    \ifempty{\@LetterEnclosureBody}
    {%
      \clearpage%
      \markboth{}{}%
      \thispagestyle                    {empty}%
      \mbox{}%
      \cleardoublepage%
      \mbox{}%
      \phantomsection%
      \mbox{}\\[-\normalbaselineskip]\nopagebreak%
      \addsectiontocentry{}             {\@LetterEnclosureTitle}%
      \unskip\ignorespaces\@LetterEnclosureBody%
    }%
  \end{document}
}

%% Set Enclosure
\newcommand{\theEnclosure               }[3][\IfLanguageNeme{ngerman}{Anlage}{Enclosure}]
{
  \def\@LetterEnclosureTitle            {#1}
  \def\@LetterEnclosureList             {#2}
  \def\@LetterEnclosureBody             {#3}
}

\newcommand{\enclosureSection           }[2]%
{%
  \phantomsection%
  \mbox{}\\[-\normalbaselineskip]\nopagebreak%
  \addsubsectiontocentry{}              {#1}%
  \markleft                             {#1}%
  \ignorespaces#2\clearpage%
}%

%% Set Receiver
\newcommand{\theReceiver                }[5][]
{
  \def\@LetterReceiverInstituteShort    {#1}
  \def\@LetterReceiverInstituteLong     {#2}
  \theReceiverName                      #3{}{}{}
  \theReceiverStreet                    #4{}{}
  \theReceiverCity                      #5{}{}
}

\newcommand{\theReceiverCity            }[3][]
{
  \def\@LetterReceiverCountry           {#1}
  \def\@LetterReceiverPostalCode        {#2}
  \def\@LetterReceiverMunicipality      {#3}
}

\newcommand{\theReceiverName            }[3][]
{
  \def\@LetterReceiverTitle             {#1}
  \def\@LetterReceiverFirstName         {#2}
  \def\@LetterReceiverLastName          {#3}
}

\newcommand{\theReceiverStreet          }[3][]
{
  \def\@LetterReceiverStreetExtra       {#1}
  \def\@LetterReceiverStreet            {#2}
  \def\@LetterReceiverStreetNumber      {#3}
}

%% Set Sender
\newcommand{\theSender                  }[9][]
{
  \def\@LetterSenderLogo                {#1}
  \theSenderName                        #2{}{}{}
  \theSenderStreet                      #3{}{}
  \theSenderCity                        #4{}{}
  \def\@LetterSenderTelephone           {#5}
  \def\@LetterSenderFax                 {#6}
  \def\@LetterSenderMobile              {#7}
  \theSenderEMail                       #8{}
  \def\@LetterSenderHomepage            {#9}
}

\newcommand{\theSenderCity              }[3][]
{
  \def\@LetterSenderCountry             {#1}
  \def\@LetterSenderPostalCode          {#2}
  \def\@LetterSenderMunicipality        {#3}
}

\newcommand{\theSenderEMail             }[2][]
{
  \def\@LetterSenderKey                 {#1}
  \def\@LetterSenderEMail               {#2}
}

\newcommand{\theSenderName              }[4][]
{
  \def\@LetterSenderTitle               {#1}
  \def\@LetterSenderFirstName           {#2}
  \def\@LetterSenderLastName            {#3}
  \def\@LetterSenderNickName            {#4}
}

\newcommand{\theSenderStreet            }[3][]
{
  \def\@LetterSenderStreetExtra         {#1}
  \def\@LetterSenderStreet              {#2}
  \def\@LetterSenderStreetNumber        {#3}
}
\makeatother