NAME

       Mail::SpamAssassin::Message - decode, render, and hold an RFC-2822 message

DESCRIPTION

       This module encapsulates an email message and allows access to the various MIME message
       parts and message metadata.

       The message structure, after initiating a parse() cycle, looks like this:

         Message object, also top-level node in Message::Node tree
            |
            +---> Message::Node for other parts in MIME structure
            |       |---> [ more Message::Node parts ... ]
            |       [ others ... ]
            |
            +---> Message::Metadata object to hold metadata

PUBLIC METHODS

       new()
           Creates a Mail::SpamAssassin::Message object.  Takes a hash reference as a parameter.
           The used hash key/value pairs are as follows:

           "message" is either undef (which will use STDIN), a scalar - a string containing an
           entire message, a reference to such string, an array reference of the message with one
           line per array element, or either a file glob or an IO::File object which holds the
           entire contents of the message.

           Note: The message is expected to generally be in RFC 2822 format, optionally including
           an mbox message separator line (the "From " line) as the first line.

           "parse_now" specifies whether or not to create the MIME tree at object-creation time
           or later as necessary.

           The parse_now option, by default, is set to false (0).  This allows SpamAssassin to
           not have to generate the tree of Mail::SpamAssassin::Message::Node objects and their
           related data if the tree is not going to be used.  This is handy, for instance, when
           running "spamassassin -d", which only needs the pristine header and body which is
           always handled when the object is created.

           "subparse" specifies how many MIME recursion levels should be parsed.  Defaults to 20.

       find_parts()
           Used to search the tree for specific MIME parts.  See
           Mail::SpamAssassin::Message::Node for more details.

       get_pristine_header()
           Returns pristine headers of the message.  If no specific header name is given as a
           parameter (case-insensitive), then all headers will be returned as a scalar, including
           the blank line at the end of the headers.

           If called in an array context, an array will be returned with each specific header in
           a different element.  In a scalar context, the last specific header is returned.

           ie: If 'Subject' is specified as the header, and there are 2 Subject headers in a
           message, the last/bottom one in the message is returned in scalar context or both are
           returned in array context.

           Btw, returning the last header field (not the first) happens to be consistent with
           DKIM signatures, which search for and cover multiple header fields bottom-up according
           to the 'h' tag. Let's keep it this way.

           Note: the returned header will include the ending newline and any embedded whitespace
           folding.

       get_mbox_separator()
           Returns the mbox separator found in the message, or undef if there wasn't one.

       get_body()
           Returns an array of the pristine message body, one line per array element.

       get_pristine()
           Returns a scalar of the entire pristine message.

       get_pristine_body()
           Returns a scalar of the pristine message body.

       get_pristine_body_digest()
           Returns SHA1 hex digest of the pristine message body.  CRLF line endings are
           normalized to LF before hashing.

       get_msgid()
           Returns Message-ID header for the message, with <> and surrounding whitespace removed.
           Returns undef, if nothing found between <>.

       generate_msgid()
           Generate a calculated "Message-ID" in sha1hex@sa_generated format, using To, Date
           headers and pristine body as source for hashing.

       extract_message_metadata($permsgstatus)
       $str = get_metadata($hdr)
       put_metadata($hdr, $text)
       delete_metadata($hdr)
       $str = get_all_metadata()
       finish_metadata()
           Destroys the metadata for this message.  Once a message has been scanned fully, the
           metadata is no longer required.   Destroying this will free up some memory.

       finish()
           Clean up an object so that it can be destroyed.

       receive_date()
           Return a time_t value with the received date of the current message, or current time
           if received time couldn't be determined.

PARSING METHODS, NON-PUBLIC

       These methods take a RFC2822-esque formatted message and create a tree with all of the
       MIME body parts included.  Those parts will be decoded as necessary, and text/html parts
       will be rendered into a standard text format, suitable for use in SpamAssassin.

       parse_body()
           parse_body() passes the body part that was passed in onto the correct part parser,
           either _parse_multipart() for multipart/* parts, or _parse_normal() for everything
           else.  Multipart sections become the root of sub-trees, while everything else becomes
           a leaf in the tree.

           For multipart messages, the first call to parse_body() doesn't create a new sub-tree
           and just uses the parent node to contain children.  All other calls to parse_body()
           will cause a new sub-tree root to be created and children will exist underneath that
           root.  (this is just so the tree doesn't have a root node which points at the actual
           root node ...)

       _parse_multipart()
           Generate a root node, and for each child part call parse_body() to generate the tree.

       _parse_normal()
           Generate a leaf node and add it to the parent.