NAME

       tnef - decode Microsoft's Transport Neutral Encapsulation Format

SYNOPSIS

       tnef [options] [FILE]

       tnef {--help | --version}

DESCRIPTION

       This  manual  page  documents  the  tnef  filter.  tnef decodes e-mail attachments encoded in Microsoft's
       Transport Neutral Encapsulation Format (hereafter, TNEF), which "wraps" Microsoft e-mail attachments.

       Unfortunately, these "wrapped" attachments are inaccessible to any e-mail client that does not understand
       TNEF.  Fortunately, the tnef filter can be used by any MIME-aware client to unpack these attachments.

OPTIONS

       -f FILE,  --file=FILE
              use FILE as input ('-' denotes stdin).  When this option is omitted, tnef reads data from stdin.

       -C DIR,  --directory=DIR
              unpack file attachments into DIR.

       -x SIZE, --maxsize=SIZE
              limit maximum size of extracted archive (bytes)

       -t, --list
              list attached files, do not extract. For each file in the datafile the file  name  and  full  path
              will be printed.

              If  the verbose option is also provided then this option acts as the --list-with-mime-types option
              and also prints the file length (in bytes) and the date of the file before the other data.

       --list-with-mime-types
              same as list option but also prints MIME type and content ID of each file after filename and  file
              path.

       -w,  --interactive,  --confirmation
              ask for confirmation for every action.

       --overwrite
              when extracting attachments, overwrite existing files.

       --number-backups
              when extracting attachments, if file FOO will be overwritten, create FOO.n instead.

       --use-paths
              honor  file  pathnames  specified in the TNEF attachment.  For security reasons, paths to attached
              files are ignored by default.

       --save-body FILE
              Save message body data found in the TNEF data. By default tnef only extracts  the  attached  files
              and not the message body.

              There  can  be  up to three message bodies in the file, plain text, HTML encoded, and RTF encoded.
              Which are saved is specified by the --body-pref option. By default the message bodies are  written
              to a file named message with an extension based upon the type (txt, html, rtf).

       --body-pref PREF
              Specifies which of the possibly three message body formats will be saved.  PREF can be up to three
              characters  long  and each character must be one of 'r', 'h', or 't' specifying RTF, HTML or text.
              The order is the order that the data will be checked, the first type found will be saved.  If PREF
              is the special value of 'all' then any and all message body data found will be saved.  The default
              is 'rht'.

       --save-rtf FILE
              DEPRECATED.  Equivalent to --save-body=FILE --body-pref=r

       -h,  --help
              show usage message.

       -V,  --version
              display version and copyright.

       -v,  --verbose
              produce verbose output.

       --debug
              enable debug output. (This will produce a very large amount of output.)

KNOWN LIMITATIONS

       tnef ignores the OEMCodePage data in the data file. It assumes Unicode data.

EXAMPLE

       The following example demonstrates typical tnef usage with a popular Unix mail client called "mutt".

   Step 1 — Configure ~/.mailcap
       Mutt can't use tnef for its intended purpose until an  appropriate  content  type  definition  exists  in
       ~/.mailcap.  Here's a sample definition:

              application/ms-tnef; tnef -w %s

       This mailcap entry says that whenever the MIME content type:

              application/ms-tnef

       is encountered, use this command to decode it:

              tnef -w %s

       The  latter  command  string invokes tnef, specifying both the -w option and the attachment (created as a
       temporary file) as command line arguments.

   Step 2 — Add The Filter To $PATH
       Mutt can't invoke tnef if the filter isn't accessible via $PATH.

   Step 3 — Test Mutt
       Use mutt to read a message that includes a TNEF attachment.  Mutt will note that an  attachment  of  type
       "application/ms-tnef is unsupported".

       Press the "v" key to open mutt's "view attachment" menu.

       Move  the  cursor  over  the TNEF attachment and press the enter key to "view" the attachment.  Mutt will
       launch tnef and invoke it using the command line syntax specified in ~/.mailcap (step 1).  tnef then  de‐
       codes  all file(s) included in the TNEF attachment, prompting for confirmation prior to creating an indi‐
       vidual file (refer to -w option above).  -w is useful here because it gives the end user a chance to view
       the filename(s) included in the mail message.

       Note that Mutt's attachment menu also supports a pipe option, which permits the user to pipe  attachments
       to  an external filter (how convenient).  So, to list the contents of a TNEF attachment prior to decoding
       it, press the "|" key and enter this command:

              tnef -t

SEE ALSO

       metamail(1), mailcap(4), mutt(1), other email clients.

AUTHOR

       Mark Simpson <verdammelt@gmail.com>

REPORTING BUGS

       Please     report     issues     via     this      project's      issue      tracker      on      GitHub:
       https://github.com/verdammelt/tnef/issues

OTHER REFERENCES

       This web page:

       https://www.dwheeler.com/essays/microsoft-outlook-tnef.html

       describes  how to configure Microsoft email clients so that the TNEF format is disabled when sending mes‐
       sages to non-TNEF-compatible clients.

                                                                                                         TNEF(1)