Print box drawing characters with pdfLaTeX

You can use the symbols, if available on the keyboard, or the macros.

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{pmboxdraw}
\usepackage{newunicodechar}
\newunicodechar{└}{\textSFii}
\newunicodechar{├}{\textSFviii}
\newunicodechar{─}{\textSFx}
\begin{document}

\begin{verbatim}
├── Maildir/
└── scripts/
    ├── backup.sh*
    └── OLD/
        ├── backup_cleanup.sh.old
        └── backup.sh.old*
\end{verbatim}

\end{document}

This is an extension to Herbert's answer and an answer to Tobia's comment.

Package inputenc with encoding option utf8 allows the use of UTF-8 in TeX input files with 8-bit TeX engines. As prerequisite, the Unicode characters must be known, how they are mapped to TeX code. The UTF-8 support of inputenc couples this with the font encoding. Therefore package pmboxdraw defines an artificial font encoding pmboxdraw and the related mapping file pmboxdrawenc.dfu, which is then automatically loaded. This simplifies Herbert's example to:

% arara: pdflatex
\listfiles
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{pmboxdraw}

\begin{document}
\begin{verbatim}
├── Maildir/
└── scripts/
    ├── backup.sh*
    └── OLD/
        ├── backup_cleanup.sh.old
        └── backup.sh.old*
\end{verbatim}

\end{document}

Compiled with:

This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016)

Version list of \listfiles:

 *File List*
 article.cls    2014/09/29 v1.4h Standard LaTeX document class
  size10.clo    2014/09/29 v1.4h Standard LaTeX file (size option)
 fontenc.sty
   t1enc.def    2005/09/27 v1.99g Standard LaTeX file
inputenc.sty    2015/03/17 v1.2c Input encoding file
    utf8.def    2016/02/28 v1.1s UTF-8 support for inputenc
   t1enc.dfu    2016/02/28 v1.1s UTF-8 support for inputenc
  ot1enc.dfu    2016/02/28 v1.1s UTF-8 support for inputenc
  omsenc.dfu    2016/02/28 v1.1s UTF-8 support for inputenc
pmboxdraw.sty    2011/03/24 v1.1 Poor man's box drawing characters (HO)
 ltxcmds.sty    2011/11/09 v1.22 LaTeX kernel commands for general use (HO)
kvsetkeys.sty    2012/04/25 v1.16 Key value parser (HO)
infwarerr.sty    2010/04/08 v1.3 Providing info/warning/error messages (HO)
etexcmds.sty    2011/02/16 v1.5 Avoid name clashes with e-TeX commands (HO)
ifluatex.sty    2010/03/01 v1.3 Provides the ifluatex switch (HO)
kvdefinekeys.sty    2011/04/07 v1.3 Define keys (HO)
pmboxdrawenc.dfu    2011/03/24 v1.1 UTF-8 support for box drawing characters
kvoptions.sty    2011/06/30 v3.11 Key value format for package options (HO)
  keyval.sty    2014/10/28 v1.15 key=value parser (DPC)
  t1cmtt.fd    2014/09/29 v2.5h Standard LaTeX font definitions
 ***********

LuaTeX/XeTeX version

LuaTeX and XeTeX support Unicode characters and package inputenc is deprecated. However, pmboxdrawenc.dfu can still be used to make the supported characters active and expand to the symbols:

% arara: xelatex
% or
% arara: lualatex
\documentclass{article}
\usepackage{pmboxdraw}

\begingroup
  \def\DeclareUnicodeCharacter#1{%
    \begingroup
      \lccode`\~="#1\relax
    \lowercase{\endgroup
      \global\catcode`~=\active
      \gdef~%
    }%
  }%
  \input{pmboxdrawenc.dfu}%
\endgroup

\begin{document}
\begin{verbatim}
├── Maildir/
└── scripts/
    ├── backup.sh*
    └── OLD/
        ├── backup_cleanup.sh.old
        └── backup.sh.old*
\end{verbatim}

\end{document}