faxmail - mail-to-fax gateway application

faxmail [ options ] [ destination [ from ] ]

faxmail takes an electronic mail message on standard input and converts it to in a form that is suitable for transmission as a facsimile. The converted document is either written to the standard output or, if direct delivery is enabled, it is submitted directly to a server for transmission.

faxmail is designed for use in constructing electronic mail to facsimile gateway services. For example, mail aliases may be created to automatically transmit electronic mail; e.g.

sam: "|/usr/bin/faxmail -d sam@5551212"

If faxmail is invoked without enabling direct delivery then it just formats the mail message on the standard input and writes the result to the standard output. To enable direct delivery the -d option must be specified on the command line; see below for more information.

faxmail formats a mail message according to the following rules: First it parses the envelope information interpreting any meta-header information (see below) that is present. Once the entire envelope has been collected it emits a formatted set of header lines. By default all header information except the ``From'', ``To'', ``Cc'', ``Subject'', and ``Date'' lines are discarded. Header lines that are kept have the tag (the string to the left of the ``:'') set in a bold font and the value (the string to the right of the ``:'') set in an italic font. Mail messages that conform to the Multipurpose Internet Mail Extensions (MIME) specification are parsed and handled according to the rules given below. Plain text body parts of a mail message are formatted in a text font with any long lines wrapped at word boundaries unless the -c option has been specified.

By default, faxmail sets all text in 10 point type on an 8.5" by 11" portrait-oriented page with .35" top margin, .25" bottom margin and .25" left and right hand margins. There are command-line options to control the point size, page dimensions, orientation, and multi-column formatting. Text formatting can also be controlled through meta-header directives placed in the envelope of the mail message.

faxmail pre-processes the envelope information (i.e. the header lines) before formatting the message contents. Header lines whose names begin with ``X-FAX-'' (case-insensitive) are handled specially-they are treated as command directives that specify how to generate the resultant or, optionally, how to deliver the resulting document as facsimile. The set of known meta-headers corresponds to the set of configuration parameters defined below. A meta-header is specified as ``X-FAX-parameter'' where parameter is the name of a configuration parameter; e.g. ``X-FAX-TabStop'' to set the number of spaces between tab stops.

Controls for specifying headers to be passed through in the formatted text identify not only which headers but also the order in which the headers should be emitted. faxmail initializes the set of headers to retain to: ``To From Subject Cc Date''. If this order is acceptable then additional headers can simply be added with the X-FAX-Headers directive; e.g. ``X-FAX-Headers: Message-id''. If however a different order is desired then the header set should be cleared with a ``clear'' header tag and then completely specified in the desired order; for example,

X-FAX-Headers: clear Message-id Date To Subject From Cc

will cause headers to be emitted in the order ``Message-Id Date To Subject From Cc'' (depending on what headers are present). Note in particular that all header lines in the envelope can be suppressed by specifying ``X-FAX-Headers: clear''; this is useful, for example, when the body of the mail message contains a preformatted document that is to be transmitted.

In addition to the above controls, faxmail can also be instructed to substitute an arbitrary string for a header tag when generating the final envelope. This facility can be used to better format ad-hoc header information that is passed through the envelope of the message. The ``X-FAX-MapHeader'' meta-header specifies how to map a header line. For example,

X-FAX-MapHeader: x_FAX_For Deliver FAX To

faxmail parses MIME mail messages and does some rudimentary work to:

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strip out unprintable content such as audio, video, or binary data,

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decode encoded parts,

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insert ``digest dividers'' between multipart/digest subparts,

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format message/rfc822 parts as described above for the top-level envelope, and

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optionally convert graphical parts (e.g. images) for display.

MIME processing is fairly simple and (currently) somewhat constrained. faxmail has builtin support for the following MIME parts: text/plain, multipart/mixed, multipart/digest, message/rfc822, application/postscript, and application/x-faxmail-prolog. Parts can also be processed through external processing scripts that faxmail looks for in a ``MIME converters'' directory hierarchy. External scripts may override builtin processing or supplement the builtin support. For each MIME body part with type T and subtype S faxmail checks first for an executable script named T/S in the converter hierarchy. If a script exists then it is run and the result is appended to the output PostScript document. Otherwise if the part has builtin support then it is processed directly. Any part that does not have external or builtin support is discarded and replaced by a message that indicates the part was removed. This discarded message can be suppressed with the MarkDiscarded configuration parameter (also settable with an X-FAX-MarkDiscarded line in the envelope).

The builtin handling support is as follows: text/plain parts are formatted using the default text font and point size; multipart/mixed are ``burst'' and interpreted per the specification but are otherwise unformatted; multipart/digest are burst and an optional ``digest divider'' marking may be inserted before each subpart; message/rfc822 are formatted as described above with envelope header lines culled and formatted with bold and italic fonts (in addition, if there is insufficient space in the current output page/column for the message envelope, optional divider, and one line of text, then faxmail will insert a ``break'' so the the message starts at the top of the next page/column); application/postscript are copied through untouched to the output; application/x-faxmail-prolog are copied through untouched to the end of the prologue section of the generated PostScript document to permit customization of the formatted output.

faxmail supports the following Content-Transfer-Encoding schemes: 7bit, 8bit, binary, base64, quoted-printable, and x-uuencode. Any character set that is not us-ascii is treated as iso-8859-1.

In general it is recommended that senders either permit faxmail to format message contents or completely bypass the formatting facilities and submit data that is to be processed by sendfax. Trying to combine the two facilities by, for example, combining PostScript with text that is to be formatted is unlikely to work well because faxmail does not track the amount of space on the page that a non-text MIME part uses.

When faxmail is invoked with the -d option it delivers the formatted document directly to a server for transmission as facsimile. Command line arguments may be supplied to specify the delivery destination and sender identity; typically from information extracted by the mail transport facility. A command line destination is specified with the same syntax as the argument for the -d option to the sendfax(1) command. Similarly any from identity specified on the command line follows the same rules as the -f option to sendfax. An explicit dialstring to use in delivery can also be specified with an X-FAX-Dialstring header in the mail message envelope. If no sender identity is provided on the command line then faxmail will extract it from the ``From'' line in the envelope. faxmail will not submit a message for delivery if either the dialstring or sender identity is missing or null.

When direct delivery is enabled X-FAX- header lines may be included in the mail message envelope to control the submission and delivery process. As above these lines are specified as ``X-FAX-parameter'' where parameter is the name of a configuration parameter for the sendfax program; e.g. ``X-FAX-VRes'' to set the vertical resolution of the transmitted facsimile. By default automatic cover page generation is enabled when direct delivery is used; this can be overridden with the -n option on the command line or by including an X-FAX-AutoCoverPage header in the message envelope.

-1

Set text in one column (default).

-2

Set text two columns.

-b font

Make font, a font name, the ``bold font'' used to set header lines. The default bold font is Helvetica-Bold.

-c

Clip long text lines instead of wrapping them at page margins.

-d

Enable direct delivery of facsimile; the formatted document will be submitted directly to a server for transmission as facsimile. This option is similar to piping the output of faxmail to the input of sendfax(8) except when direct delivery is enabled faxmail interprets ``x-fax-'' header lines in the envelope of the mail message to look for control information to use in delivering the facsimile and, by default, no automatic cover page generation is done.

-f font

Make font, a font name, the text font used to set the body of mail messages. The default text font is Courier.

-H height

Use height as the height, in inches, of the output page. The default page height is taken from the default page size.

-i font

Make font, a font name, the ``italic font'' used to set header lines. The default italic font is Helvetica-Oblique.

-Ml=#,r=#,t=#,b=#

Set the page margins; the default margins are: left and right .25 inch, top .35 inch, bottom .25 inch.

-n

Suppress auto cover page generation when doing direct delivery.

-p size

Set all text using size for the font point size.

-r

Set pages rotated by 90 degrees (in ``Landscape mode'').

-R

Set pages unrotated (in ``Portrait mode'').

-s size

Set the page size to use. Cover pages are normally generated using a system-default page size (usually letter-size pages, 8.5" by 11", for sites in North America). Alternate page sizes are specified symbolically using either the name or abbreviation of an entry in the pagesizes(5) database; e.g. a3 (ISO A3), a4 (ISO A4), a5 (ISO A5), a6 (ISO A6), b4 (ISO B4), na-let (North American Letter), us-leg (American Legal), us-led (American Ledger), us-exe (American Executive), jp-let (Japanese Letter), and jp-leg (Japanese Legal). Comparisons are case-insensitive and any match of a substring of the full page-size name is sufficient; e.g. ``legal'' would match ``American Legal''.

-u user

Set the user name to use when logging in to do direct delivery. By default the user is specified by the MailUser configuration parameter (see below). If a null user name is specified, then the facsimile will be submitted using the identity of the user that invoked faxmail.

-v

Enable tracing of envelope, MIME, and job submission processing. Diagnostic information is written to the standard error (envelope and MIME processing) and standard output (job submission).

-W width

Use width as the width, in inches, of the output page. The default page width is taken from the default page size.

faxmail reads configuration information from the files /etc/hylafax/hyla.conf, and ~/.hylarc; in that order. Configuration files follow the conventions described in hylafax-client(1). The following configuration parameters are recognized:

Tag	Type	Default	Description
AutoCoverPage	boolean	Yes	automatically generate cover page
BoldFont	string	Helvetica-Bold	font for setting header tags
Columns	integer	1	number of columns in formatted output
DigestDivider	string	-	multipart/digest divider  command
FontPath	string	see below	directory for font metric files
GaudyHeaders	boolean	No	enable/disable gaudy page headers
Headers	string	see below	headers to retain in envelope
ISO8859	boolean	Yes	use ISO 8859-1 character encoding
ItalicFont	string	Helvetica-Oblique	font for setting header values
LineWrap	boolean	Yes	wrap/truncate text lines
MailUser	string	-	user identity for doing direct delivery
MarkDiscarded	boolean	Yes	mark discarded MIME body parts
MapHeader	string	-	define header mapping
MIMEConverters	string	see below	pathname of MIME converter scripts
Orientation	string	portrait	orientation of text on page
OutlineMargin	inches	0	width of outline line
PageCollation	string	forward	collate pages in forward or reverse direction
PageHeaders	boolean	Yes	enable/disable page headers
PageHeight	float	-	output page height
PageMargins	string	see below	margins for formatted page
PageSize	string	default	output page size from database
PageWidth	float	-	output page width
Prologfile	string	see below	pathname of  prologue file
TabStop	integer	8	inter-stop setting in characters
TextFont	string	Courier	name of font for setting text
TextLineHeight	inches	-	text formatting line height control
TextPointSize	inches	see below	size to use in setting text
Verbose	boolean	No	trace envelope and MIME processing

Values marked as inches are specified using a syntax that identifies one of several possible units:

#.##bp	big point (1in = 72bp)
#.##cc	cicero (1cc = 12dd)
#.##cm	centimeter
#.##dd	didot point (1157dd = 1238pt)
#.##in	inch
#.##mm	millimeter (10mm = 1cm)
#.##pc	pica (1pc = 12pt)
#.##pt	point (72.27pt = 1in)
#.##sp	scaled point (65536sp = 1pt)

Unit names can be upper or lower case but no white space is permitted between the number and the unit. Values specified with no unit are interpreted as points.

The configuration parameters are explained below. Most parameters correspond to a command line option. Parameter values identified above as inches are converted according to the conventions described above.

AutoCoverPage

Control whether or not a cover page is automatically generated for each job.

BoldFont

The name of the font to use to set header tags (i.e. the string to the left of the ``:'').

Columns

The number of columns to set text in. (Equivalent to the -m option.)

DigestDivider

The string to emit in the output before each subpart of a multipart/digest mail message. This string is typically a procedure that draws a mark of some sort. Dividers are expected to use no more vertical space on the output page than a line of text.

FontPath

The path where Adobe Font Metric (AFM) files are located; by default /usr/share/enscript/afm:/usr/share/fonts/afms/adobe:/usr/share/fonts/type1/gsfonts.

GaudyHeaders

Control whether or not to use a gaudy-style page header. Enabling gaudy headers implicitly enables page headers.

Headers

Define the headers retained from the envelope and specify the order that they should be emitted in the formatted output. The set of headers is initialized to ``To From Subject Cc Date''. Headers specified are appended to this list except for a ``clear'' header that causes the current set of headers to be discarded.

ISO8859

Control the use of ISO 8859-1 encoding in the generated

ItalicFont

The name of the font to use to set header values (i.e. the string to the right of the ``:'').

LineWrap

Control whether long text lines are wrapper or truncated at the right hand margin. (Equivalent to the -c option.)

MailUser

The account name to use to login to a fax server when doing direct delivery. Note that this account name is not used for the identity of the sender; this comes from the command line or the ``From'' line in the mail message. If a null account name is specified, then the facsimile will be submitted using the identity of the user that invoked faxmail.

MapHeader

Define a substitution for the specified header that should be done each time the header is emitted in the formatted envelope. Header tags are matched in a case-insensitive manner.

MarkDiscarded

Control whether discarded MIME parts are replaced by a text message indicating the original content was removed.

MIMEConverters

The pathname of a directory hierarchy that has scripts for external processing of MIME body parts. The default pathname is /usr/sbin/faxmail.

Orientation

Control whether pages are oriented horizontally (``landscape'') or vertically (``portrait''). (Equivalent to the -r and -R options.)

OutlineMargin

Control whether columns of text have a line drawn around them and the width of the line. Setting this parameter to 0 disables outlines.

PageCollation

Control whether the output file has pages collated in the same order as the input file (``forward'') or in reverse order (``reverse).

PageHeaders

Control whether page headers are generated.

PageHeight

Set the output page height (in inches).

PageMargins

Set the output page margins. Margins are specified as string of the form: ``l=#,r=#,t=#,b=#'' where l indicates the left margin, r indicates the right margin, t indicates the top margin, b indicates the bottom margin, and numbers are interpreted as inches. (Equvalent to the -M option.)

PageSize

Set the output page dimensions by name. (Equivalent to the -s option.)

PageWidth

Set the output page width (in inches).

PrologFile

The pathname of a file containing that should be included in the prologue section of the generated . The default prologue file is /etc/hylafax/faxmail.ps.

TabStop

Set the tab stop distance (in characters).

TextFont

Set the name of font to use for setting text. (Equivalent to the -f option.)

TextLineHeight

Set the vertical text line height and spacing.

TextPointSize

Set the point size to use in setting plain text. (Equvalent to the -p option.)

Verbose

Control tracing envelope and MIME processing.

Because a sender's identity in an electronic mail message is inherently untrustworthy, using faxmail to build a mail to fax gateway is problematic. Unless mail service is somehow restricted or the sender's identity is verified using a mechanism such as RFC 1847's multipart/signed MIME type there is no reliable way to restrict access to facilities setup with faxmail.

Only the last instance of a header is kept and written to the output. This means, for example, that only the last of many ``Received'' lines will be included in the formatted output.

~/.hylarc	per-user configuration file
/etc/hylafax/pagesizes	page size database
/etc/hylafax/faxmail.ps	 prologue
/etc/hylafax/hyla.conf	system-wide configuration file
/etc/hylafax/faxmail.conf	system-wide configuration file
/etc/hylafax/sendfax.conf	system-wide configuration file for direct delivery
/usr/sbin/faxmail	hierarchy for external MIME converters
/usr/share/enscript/afm:/usr/share/fonts/afms/adobe:/usr/share/fonts/type1/gsfonts	for font metrics
/var/spool/hylafax/tmp/faxmailXXXXXX	temporary files

hylafax-client(1), textfmt(1), sendfax(1)