Provided by: libmail-message-perl_3.006-1_all bug

NAME

       Mail::Message - general message object

INHERITANCE

        Mail::Message has extra code in
          Mail::Message::Construct
          Mail::Message::Construct::Bounce
          Mail::Message::Construct::Build
          Mail::Message::Construct::Forward
          Mail::Message::Construct::Read
          Mail::Message::Construct::Rebuild
          Mail::Message::Construct::Reply
          Mail::Message::Construct::Text

        Mail::Message
          is a Mail::Reporter

        Mail::Message is extended by
          Mail::Box::Message
          Mail::Message::Dummy
          Mail::Message::Part
          Mail::Message::Replace::MailInternet

SYNOPSIS

        use Mail::Box::Manager;
        my $mgr    = Mail::Box::Manager->new;
        my $folder = $mgr->open(folder => 'InBox');
        my $msg    = $folder->message(2);    # $msg is a Mail::Message now

        my $subject = $msg->subject;         # The message's subject
        my @cc      = $msg->cc;              # List of Mail::Address'es

        my Mail::Message::Head $head = $msg->head;
        my Mail::Message::Body $body = $msg->decoded;
        $msg->decoded->print($outfile);

        # Send a simple email
        Mail::Message->build
          ( To             => 'you@example.com'
          , From           => 'me@example.com'
          , Subject        => "My subject"
          , data           => "Some plain text content"
          )->send(via => 'postfix');

        my $reply_msg = Mail::Message->reply(...);
        my $frwd_msg  = Mail::Message->forward(...);

DESCRIPTION

       A "Mail::Message" object is a container for MIME-encoded message information, as defined
       by RFC2822.  Everything what is not specificaly related to storing the messages in
       mailboxes (folders) is implemented in this class.  Methods which are related to folders is
       implemented in the Mail::Box::Message extension.

       The main methods are get(), to get information from a message header field, and decoded()
       to get the intended content of a message.  But there are many more which can assist your
       program.

       Complex message handling, like construction of replies and forwards, are implemented in
       separate packages which are autoloaded into this class.  This means you can simply use
       these methods as if they are part of this class.  Those package add functionality to all
       kinds of message objects.

       Extends "DESCRIPTION" in Mail::Reporter.

METHODS

       Extends "METHODS" in Mail::Reporter.

   Constructors
       Extends "Constructors" in Mail::Reporter.

       $obj->clone(%options)
           Create a copy of this message.  Returned is a "Mail::Message" object.  The head and
           body, the log and trace levels are taken.  Labels are copied with the message, but the
           delete and modified flags are not.

           BE WARNED: the clone of any kind of message (or a message part) will always be a
           "Mail::Message" object.  For example, a Mail::Box::Message's clone is detached from
           the folder of its original.  When you use Mail::Box::addMessage() with the cloned
           message at hand, then the clone will automatically be coerced into the right message
           type to be added.

           See also Mail::Box::Message::copyTo() and Mail::Box::Message::moveTo().

            -Option      --Default
             shallow       <false>
             shallow_body  <false>
             shallow_head  <false>

           shallow => BOOLEAN
             When a shallow clone is made, the header and body of the message will not be cloned,
             but shared.  This is quite dangerous: for instance in some folder types, the header
             fields are used to store folder flags.  When one of both shallow clones change the
             flags, that will update the header and thereby be visible in both.

             There are situations where a shallow clone can be used safely.  For instance, when
             Mail::Box::Message::moveTo() is used and you are sure that the original message
             cannot get undeleted after the move.

           shallow_body => BOOLEAN
             A rather safe bet, because you are not allowed to modify the body of a message: you
             may only set a new body with body().

           shallow_head => BOOLEAN
             Only the head uses is reused, not the body.  This is probably a bad choice, because
             the header fields can be updated, for instance when labels change.

           example:

            $copy = $msg->clone;

       Mail::Message->new(%options)
            -Option    --Defined in     --Default
             body                         undef
             body_type                    Mail::Message::Body::Lines
             deleted                      <false>
             field_type                   undef
             head                         undef
             head_type                    Mail::Message::Head::Complete
             labels                       {}
             log         Mail::Reporter   'WARNINGS'
             messageId                    undef
             modified                     <false>
             trace       Mail::Reporter   'WARNINGS'
             trusted                      <false>

           body => OBJECT
             Instantiate the message with a body which has been created somewhere before the
             message is constructed.  The OBJECT must be a sub-class of Mail::Message::Body.  See
             also body() and storeBody().

           body_type => CLASS
             Default type of body to be created for readBody().

           deleted => BOOLEAN
             Is the file deleted from the start?

           field_type => CLASS
           head => OBJECT
             Instantiate the message with a head which has been created somewhere before the
             message is constructed.  The OBJECT must be a (sub-)class of Mail::Message::Head.
             See also head().

           head_type => CLASS
             Default type of head to be created for readHead().

           labels => ARRAY|HASH
             Initial values of the labels.  In case of Mail::Box::Message's, this shall reflect
             the state the message is in.  For newly constructed Mail::Message's, this may be
             anything you want, because coerce() will take care of the folder specifics once the
             message is added to one.

           log => LEVEL
           messageId => STRING
             The id on which this message can be recognized.  If none specified and not defined
             in the header --but one is needed-- there will be one assigned to the message to be
             able to pass unique message-ids between objects.

           modified => BOOLEAN
             Flags this message as being modified from the beginning on.  Usually, modification
             is auto-detected, but there may be reasons to be extra explicit.

           trace => LEVEL
           trusted => BOOLEAN
             Is this message from a trusted source?  If not, the content must be checked before
             use.  This checking will be performed when the body data is decoded or used for
             transmission.

   Constructing a message
       $obj->bounce( [<$rg_object|%options>] )
           Inherited, see "Constructing a message" in Mail::Message::Construct::Bounce

       Mail::Message->build( [$message|$part|$body], $content )
           Inherited, see "Constructing a message" in Mail::Message::Construct::Build

       Mail::Message->buildFromBody($body, [$head], $headers)
           Inherited, see "Constructing a message" in Mail::Message::Construct::Build

       $obj->forward(%options)
           Inherited, see "Constructing a message" in Mail::Message::Construct::Forward

       $obj->forwardAttach(%options)
           Inherited, see "Constructing a message" in Mail::Message::Construct::Forward

       $obj->forwardEncapsulate(%options)
           Inherited, see "Constructing a message" in Mail::Message::Construct::Forward

       $obj->forwardInline(%options)
           Inherited, see "Constructing a message" in Mail::Message::Construct::Forward

       $obj->forwardNo(%options)
           Inherited, see "Constructing a message" in Mail::Message::Construct::Forward

       $obj->forwardPostlude()
           Inherited, see "Constructing a message" in Mail::Message::Construct::Forward

       $obj->forwardPrelude()
           Inherited, see "Constructing a message" in Mail::Message::Construct::Forward

       $obj->forwardSubject(STRING)
           Inherited, see "Constructing a message" in Mail::Message::Construct::Forward

       Mail::Message->read($fh|STRING|SCALAR|ARRAY, %options)
           Inherited, see "Constructing a message" in Mail::Message::Construct::Read

       $obj->rebuild(%options)
           Inherited, see "Constructing a message" in Mail::Message::Construct::Rebuild

       $obj->reply(%options)
           Inherited, see "Constructing a message" in Mail::Message::Construct::Reply

       $obj->replyPrelude( [STRING|$field|$address|ARRAY-$of-$things] )
           Inherited, see "Constructing a message" in Mail::Message::Construct::Reply

       $obj->replySubject(STRING)
       Mail::Message->replySubject(STRING)
           Inherited, see "Constructing a message" in Mail::Message::Construct::Reply

   The message
       $obj->container()
           If the message is a part of another message, "container" returns the reference to the
           containing body.

           example:

            my Mail::Message $msg = ...
            return unless $msg->body->isMultipart;
            my $part   = $msg->body->part(2);

            return unless $part->body->isMultipart;
            my $nested = $part->body->part(3);

            $nested->container;  # returns $msg->body
            $nested->toplevel;   # returns $msg
            $msg->container;     # returns undef
            $msg->toplevel;      # returns $msg
            $msg->isPart;        # returns false
            $part->isPart;       # returns true

       $obj->isDummy()
           Dummy messages are used to fill holes in linked-list and such, where only a message-id
           is known, but not the place of the header of body data.

           This method is also available for Mail::Message::Dummy objects, where this will return
           "true".  On any extension of "Mail::Message", this will return "false".

       $obj->isPart()
           Returns true if the message is a part of another message.  This is the case for
           Mail::Message::Part extensions of "Mail::Message".

       $obj->messageId()
           Retrieve the message's id.  Every message has a unique message-id.  This id is used
           mainly for recognizing discussion threads.

       $obj->partNumber()
           Returns a string representing the location of this part.  In case the top message is a
           single message, 'undef' is returned.  When it is a multipart, '1' up to the number of
           multiparts is returned.  A multi-level nested part may for instance return '2.5.1'.

           Usually, this string is very short.  Numbering follows the IMAP4 design, see RFC2060
           section 6.4.5.

       $obj->print( [$fh] )
           Print the message to the FILE-HANDLE, which defaults to the selected filehandle,
           without the encapsulation sometimes required by a folder type, like write() does.

           example:

            $message->print(\*STDERR);  # to the error output
            $message->print;            # to the selected file

            my $out = IO::File->new('out', 'w');
            $message->print($out);      # no encapsulation: no folder
            $message->write($out);      # with encapsulation: is folder.

       $obj->send( [$mailer], %options )
           Transmit the message to anything outside this Perl program.  Returns false when
           sending failed even after retries.

           The optional $mailer is a Mail::Transport::Send object.  When the $mailer is not
           specified, one will be created and kept as default for the next messages as well.

           The %options are mailer specific, and a mixture of what is usable for the creation of
           the mailer object and the sending itself.  Therefore, see for possible options
           Mail::Transport::Send::new() and Mail::Transport::Send::send().  That object also
           provides a "trySend()" method which gives more low-level control.

           example:

            $message->send;

           is short (but little less flexibile) for

            my $mailer = Mail::Transport::SMTP->new(@smtpopts);
            $mailer->send($message, @sendopts);

           See examples/send.pl in the distribution of Mail::Box.

           example:

            $message->send(via => 'sendmail')

       $obj->size()
           Returns an estimated size of the whole message in bytes.  In many occasions, the
           functions which process the message further, for instance send() or print() will need
           to add/change header lines or add CR characters, so the size is only an estimate with
           a few percent margin of the real result.

           The computation assumes that each line ending is represented by one character (like
           UNIX, MacOS, and sometimes Cygwin), and not two characters (like Windows and sometimes
           Cygwin).  If you write the message to file on a system which uses CR and LF to end a
           single line (all Windows versions), the result in that file will be at least nrLines()
           larger than this method returns.

       $obj->toplevel()
           Returns a reference to the main message, which will be the current message if the
           message is not part of another message.

       $obj->write( [$fh] )
           Write the message to the FILE-HANDLE, which defaults to the selected $fh, with all
           surrounding information which is needed to put it correctly in a folder file.

           In most cases, the result of "write" will be the same as with print().  The main
           exception is for Mbox folder messages, which will get printed with their leading 'From
           ' line and a trailing blank.  Each line of their body which starts with 'From ' will
           have an '>' added in front.

   The header
       $obj->bcc()
           Returns the addresses which are specified on the "Bcc" header line (or lines) A list
           of Mail::Address objects is returned.  "Bcc" stands for Blind Carbon Copy:
           destinations of the message which are not listed in the messages actually sent.  So,
           this field will be empty for received messages, but may be present in messages you
           construct yourself.

       $obj->cc()
           Returns the addresses which are specified on the "Cc" header line (or lines) A list of
           Mail::Address objects is returned.  "Cc" stands for Carbon Copy; the people addressed
           on this line receive the message informational, and are usually not expected to reply
           on its content.

       $obj->date()
           Method has been removed for reasons of consistency.  Use timestamp() or
           "$msg->head->get('Date')".

       $obj->destinations()
           Returns a list of Mail::Address objects which contains the combined info of active
           "To", "Cc", and "Bcc" addresses.  Double addresses are removed if detectable.

       $obj->from()
           Returns the addresses from the senders.  It is possible to have more than one address
           specified in the "From" field of the message, according to the specification.
           Therefore a list of Mail::Address objects is returned, which usually has length 1.

           If you need only one address from a sender, for instance to create a "original message
           by" line in constructed forwarded message body, then use sender().

           example: using from() to get all sender addresses

            my @from = $message->from;

       $obj->get($fieldname)
           Returns the value which is stored in the header field with the specified name.  The
           $fieldname is case insensitive.  The unfolded body of the field is returned, stripped
           from any attributes.  See Mail::Message::Field::body().

           If the field has multiple appearances in the header, only the last instance is
           returned.  If you need more complex handing of fields, then call
           Mail::Message::Head::get() yourself.  See study() when you want to be smart, doing the
           better (but slower) job.

           example: the get() short-cut for header fields

            print $msg->get('Content-Type'), "\n";

           Is equivalent to:

            print $msg->head->get('Content-Type')->body, "\n";

       $obj->guessTimestamp()
           Return an estimate on the time this message was sent.  The data is derived from the
           header, where it can be derived from the "date" and "received" lines.  For MBox-like
           folders you may get the date from the from-line as well.

           This method may return "undef" if the header is not parsed or only partially known.
           If you require a time, then use the timestamp() method, described below.

           example: using guessTimestamp() to get a transmission date

            print "Receipt ", ($message->timestamp || 'unknown'), "\n";

       $obj->head( [$head] )
           Return (optionally after setting) the $head of this message.  The head must be an
           (sub-)class of Mail::Message::Head.  When the head is added, status information is
           taken from it and transformed into labels.  More labels can be added by the LABELS
           hash.  They are added later.

           example:

            my $header = Mail::Message::Head->new;
            $msg->head($header);    # set
            my $head = $msg->head;  # get

       $obj->nrLines()
           Returns the number of lines used for the whole message.

       $obj->sender()
           Returns exactly one address, which is the originator of this message.  The returned
           Mail::Address object is taken from the "Sender" header field, unless that field does
           not exists, in which case the first address from the "From" field is taken.  If none
           of both provide an address, "undef" is returned.

           example: using sender() to get exactly one sender address

            my $sender = $message->sender;
            print "Reply to: ", $sender->format, "\n" if defined $sender;

       $obj->study($fieldname)
           Study the content of a field, like get() does, with as main difference that a
           Mail::Message::Field::Full object is returned.  These objects stringify to an utf8
           decoded representation of the data contained in the field, where get() does not
           decode.  When the field does not exist, then "undef" is returned.  See
           Mail::Message::Field::study().

           example: the study() short-cut for header fields

            print $msg->study('to'), "\n";

           Is equivalent to:

            print $msg->head->study('to'), "\n";       # and
            print $msg->head->get('to')->study, "\n";

           or better:
            if(my $to = $msg->study('to')) { print "$to\n" }
            if(my $to = $msg->get('to')) { print $to->study, "\n" }

       $obj->subject()
           Returns the message's subject, or the empty string.  The subject may have encoded
           characters in it; use study() to get rit of that.

           example: using subject() to get the message's subject

            print $msg->subject;
            print $msg->study('subject');

       $obj->timestamp()
           Get a good timestamp for the message, doesn't matter how much work it is.  The value
           returned is compatible with the platform dependent result of function time().

           In these days, the timestamp as supplied by the message (in the "Date" field) is not
           trustable at all: many spammers produce illegal or unreal dates to influence their
           location in the displayed folder.

           To start, the received headers are tried for a date (see
           Mail::Message::Head::Complete::recvstamp()) and only then the "Date" field.  In very
           rare cases, only with some locally produced messages, no stamp can be found.

       $obj->to()
           Returns the addresses which are specified on the "To" header line (or lines).  A list
           of Mail::Address objects is returned.  The people addressed here are the targets of
           the content, and should read it contents carefully.

           example: using to() to get all primar destination addresses

            my @to = $message->to;

   The body
       $obj->body( [$body] )
           Return the body of this message.  BE WARNED that this returns you an object which may
           be encoded: use decoded() to get a body with usable data.

           With options, a new $body is set for this message.  This is not for normal use unless
           you understand the consequences: you change the message content without changing the
           message-ID.  The right way to go is via

            $message = Mail::Message->buildFromBody($body);  # or
            $message = Mail::Message->build($body);          # or
            $message = $origmsg->forward(body => $body);

           The $body must be an (sub-)class of Mail::Message::Body.  In this case, information
           from the specified body will be copied into the header.  The body object will be
           encoded if needed, because messages written to file or transmitted shall not contain
           binary data.  The converted body is returned.

           When $body is "undef", the current message body will be dissected from the message.
           All relation will be cut.  The body is returned, and can be connected to a different
           message.

           example:

            my $body      = $msg->body;
            my @encoded   = $msg->body->lines;

            my $new       = Mail::Message::Body->new(mime_type => 'text/html');
            my $converted = $msg->body($new);

       $obj->contentType()
           Returns the content type header line, or "text/plain" if it is not defined.  The
           parameters will be stripped off.

       $obj->decoded(%options)
           Decodes the body of this message, and returns it as a body object.  Short for
           "$msg->body->decoded"  All %options are passed-on.

       $obj->encode(%options)
           Encode the message to a certain format.  Read the details in the dedicated manual page
           Mail::Message::Body::Encode.  The %options which can be specified here are those of
           the Mail::Message::Body::encode() method.

       $obj->isMultipart()
           Check whether this message is a multipart message (has attachments).  To find this
           out, we need at least the header of the message; there is no need to read the body of
           the message to detect this.

       $obj->isNested()
           Returns "true" for "message/rfc822" messages and message parts.

       $obj->parts( [<'ALL'|'ACTIVE'|'DELETED'|'RECURSE'|$filter>] )
           Returns the parts of this message.  Maybe a bit inconvenient: it returns the message
           itself when it is not a multipart.

           Usually, the term part is used with multipart messages: messages which are
           encapsulated in the body of a message.  To abstract this concept: this method will
           return you all header-body combinations which are stored within this message except
           the multipart and message/rfc822 wrappers.  Objects returned are "Mail::Message"'s and
           Mail::Message::Part's.

           The option default to 'ALL', which will return the message itself for single-parts,
           the nested content of a message/rfc822 object, respectively the parts of a multipart
           without recursion.  In case of 'RECURSE', the parts of multiparts will be collected
           recursively.  This option cannot be combined with the other options, which you may
           want: it that case you have to test yourself.

           'ACTIVE' and 'DELETED' check for the deleted flag on messages and message parts.  The
           $filter is a code reference, which is called for each part of the message; each part
           as "RECURSE" would return.

           example:

            my @parts = $msg->parts;           # $msg not multipart: returns ($msg)
            my $parts = $msg->parts('ACTIVE'); # returns ($msg)

            $msg->delete;
            my @parts = $msg->parts;           # returns ($msg)
            my $parts = $msg->parts('ACTIVE'); # returns ()

   Flags
       $obj->delete()
           Flag the message to be deleted, which is a shortcut for
            $msg->label(deleted => time); The real deletion only takes place on a synchronization
           of the folder.  See deleted() as well.

           The time stamp of the moment of deletion is stored as value, but that is not always
           preserved in the folder (depends on the implementation).  When the same message is
           deleted more than once, the first time stamp will stay.

           example:

            $message->delete;
            $message->deleted(1);  # exactly the same
            $message->label(deleted => 1);
            delete $message;

       $obj->deleted( [BOOLEAN] )
           Set the delete flag for this message.  Without argument, the method returns the same
           as isDeleted(), which is preferred.  When a true value is given, delete() is called.

           example:

            $message->deleted(1);          # delete
            $message->delete;              # delete (preferred)

            $message->deleted(0);          # undelete

            if($message->deleted) {...}    # check
            if($message->isDeleted) {...}  # check (preferred)

       $obj->isDeleted()
           Short-cut for
            $msg->label('deleted')

           For some folder types, you will get the time of deletion in return.  This depends on
           the implementation.

           example:

            next if $message->isDeleted;

            if(my $when = $message->isDeleted) {
               print scalar localtime $when;
            }

       $obj->isModified()
           Returns whether this message is flagged as being modified.  Modifications are changes
           in header lines, when a new body is set to the message (dangerous), or when labels
           change.

       $obj->label($label|PAIRS)
           Return the value of the $label, optionally after setting some values.  In case of
           setting values, you specify key-value PAIRS.

           Labels are used to store knowledge about handling of the message within the folder.
           Flags about whether a message was read, replied to, or scheduled for deletion.

           Some labels are taken from the header's "Status" and "X-Status" lines.  Folder types
           like MH define a separate label file, and Maildir adds letters to the message
           filename.  But the MailBox labels are always the same.

           example:

            print $message->label('seen');
            if($message->label('seen')) {...};
            $message->label(seen => 1);

            $message->label(deleted => 1);  # same as $message->delete

       $obj->labels()
           Returns all known labels. In SCALAR context, it returns the knowledge as reference to
           a hash.  This is a reference to the original data, but you shall *not* change that
           data directly: call "label" for changes!

           In LIST context, you get a list of names which are defined.  Be warned that they will
           not all evaluate to true, although most of them will.

       $obj->labelsToStatus()
           When the labels were changed, that may effect the "Status" and/or "X-Status" header
           lines of mbox messages.  Read about the relation between these fields and the labels
           in the DETAILS chapter.

           The method will carefully only affect the result of modified() when there is a real
           change of flags, so not for each call to label().

       $obj->modified( [BOOLEAN] )
           Returns (optionally after setting) whether this message is flagged as being modified.
           See isModified().

       $obj->statusToLabels()
           Update the labels according the status lines in the header.  See the description in
           the DETAILS chapter.

   The whole message as text
       $obj->file()
           Inherited, see "The whole message as text" in Mail::Message::Construct::Text

       $obj->lines()
           Inherited, see "The whole message as text" in Mail::Message::Construct::Text

       $obj->printStructure( [$fh|undef],[$indent] )
           Inherited, see "The whole message as text" in Mail::Message::Construct::Text

       $obj->string()
           Inherited, see "The whole message as text" in Mail::Message::Construct::Text

   Internals
       $obj->clonedFrom()
           Returns the $message which is the source of this message, which was created by a
           clone() operation.

       Mail::Message->coerce($message, %options)
           Coerce a $message into a Mail::Message.  In some occasions, for instance where you add
           a message to a folder, this coercion is automatically called to ensure that the
           correct message type is stored.

           The coerced message is returned on success, otherwise "undef".  The coerced message
           may be a reblessed version of the original message or a new object.  In case the
           message has to be specialized, for instance from a general Mail::Message into a
           Mail::Box::Mbox::Message, no copy is needed.  However, to coerce a Mail::Internet
           object into a Mail::Message, a lot of copying and converting will take place.

           Valid MESSAGEs which can be coerced into Mail::Message objects are of type

           •   Any type of Mail::Box::Message

           •   MIME::Entity objects, using Mail::Message::Convert::MimeEntity

           •   Mail::Internet objects, using Mail::Message::Convert::MailInternet

           •   Email::Simple objects, using Mail::Message::Convert::EmailSimple

           •   Email::Abstract objects

           Mail::Message::Part's, which are extensions of "Mail::Message"'s, can also be coerced
           directly from a Mail::Message::Body.

           example:

            my $folder  = Mail::Box::Mbox->new;
            my $message = Mail::Message->build(...);

            my $coerced = Mail::Box::Mbox::Message->coerce($message);
            $folder->addMessage($coerced);

           Simpler replacement for the previous two lines:

            my $coerced = $folder->addMessage($message);

       $obj->isDelayed()
           Check whether the message is delayed (not yet read from file).  Returns true or false,
           dependent on the body type.

       $obj->readBody( $parser, $head, [$bodytype] )
           Read a body of a message.  The $parser is the access to the folder's file, and the
           $head is already read.  Information from the $head is used to create expectations
           about the message's length, but also to determine the mime-type and encodings of the
           body data.

           The $bodytype determines which kind of body will be made and defaults to the value
           specified by new(body_type).  $bodytype may be the name of a body class, or a
           reference to a routine which returns the body's class when passed the $head as only
           argument.

       $obj->readFromParser( $parser, [$bodytype] )
           Read one message from file.  The $parser is opened on the file.  First readHead() is
           called, and the head is stored in the message.  Then readBody() is called, to produce
           a body.  Also the body is added to the message without decodings being done.

           The optional $bodytype may be a body class or a reference to a code which returns a
           body-class based on the header.

       $obj->readHead( $parser, [$class] )
           Read a head into an object of the specified $class.  The $class defaults to
           new(head_type).  The $parser is the access to the folder's file.

       $obj->recursiveRebuildPart($part, %options)
           Inherited, see "Internals" in Mail::Message::Construct::Rebuild

       $obj->storeBody($body)
           Where the body() method can be used to set and get a body, with all the necessary
           checks, this method is bluntly adding the specified body to the message.  No
           conversions, not checking.

       $obj->takeMessageId( [STRING] )
           Take the message-id from the STRING, or create one when the "undef" is specified.  If
           not STRING nor "undef" is given, the current header of the message is requested for
           the value of the 'Message-ID' field.

           Angles (if present) are removed from the id.

   Error handling
       Extends "Error handling" in Mail::Reporter.

       $obj->AUTOLOAD()
           Inherited, see "METHODS" in Mail::Message::Construct

       $obj->addReport($object)
           Inherited, see "Error handling" in Mail::Reporter

       $obj->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
       Mail::Message->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->errors()
           Inherited, see "Error handling" in Mail::Reporter

       $obj->log( [$level, [$strings]] )
       Mail::Message->log( [$level, [$strings]] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->logPriority($level)
       Mail::Message->logPriority($level)
           Inherited, see "Error handling" in Mail::Reporter

       $obj->logSettings()
           Inherited, see "Error handling" in Mail::Reporter

       $obj->notImplemented()
           Inherited, see "Error handling" in Mail::Reporter

       $obj->report( [$level] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->reportAll( [$level] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->shortSize( [$value] )
       Mail::Message->shortSize( [$value] )
           Represent an integer $value representing the size of file or memory, (which can be
           large) into a short string using M and K (Megabytes and Kilobytes).  Without $value,
           the size of the message head is used.

       $obj->shortString()
           Convert the message header to a short string (without trailing newline), representing
           the most important facts (for debugging purposes only).  For now, it only reports size
           and subject.

       $obj->trace( [$level] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->warnings()
           Inherited, see "Error handling" in Mail::Reporter

   Cleanup
       Extends "Cleanup" in Mail::Reporter.

       $obj->DESTROY()
           Inherited, see "Cleanup" in Mail::Reporter

       $obj->destruct()
           Remove the information contained in the message object.  This will be ignored when
           more than one reference to the same message object exists, because the method has the
           same effect as assigning "undef" to the variable which contains the reference.  Normal
           garbage collection will call "DESTROY()" when possible.

           This method is only provided to hide differences with messages which are located in
           folders: their Mail::Box::Message::destruct() works quite differently.

           example: of Mail::Message destruct

            my $msg = Mail::Message->read;
            $msg->destruct;
            $msg = undef;    # same

DETAILS

   Structure of a Message
       A MIME-compliant message is build upon two parts: the header and the body.

       The header

       The header is a list of fields, some spanning more than one line (folded) each telling
       something about the message. Information stored in here are for instance the sender of the
       message, the receivers of the message, when it was transported, how it was transported,
       etc.  Headers can grow quite large.

       In MailBox, each message object manages exactly one header object (a Mail::Message::Head)
       and one body object (a Mail::Message::Body).  The header contains a list of header fields,
       which are represented by Mail::Message::Field objects.

       The body

       The body contains the "payload": the data to be transferred.  The data can be encoded,
       only accessible with a specific application, and may use some weird character-set, like
       Vietnamese; the MailBox distribution tries to assist you with handling these e-mails
       without the need to know all the details.  This additional information ("meta-
       information") about the body data is stored in the header.  The header contains more
       information, for instance about the message transport and relations to other messages.

   Message object implementation
       The general idea about the structure of a message is

        Mail::Message
         |  |
         |  `-has-one--Mail::Message::Body
         |
         `----has-one--Mail::Message::Head
                         |
                         `-has-many--Mail::Message::Field

       However: there are about 7 kinds of body objects, 3 kinds of headers and 3 kinds of
       fields.  You will usually not see too much of these kinds, because they are merely created
       for performance reasons and can be used all the same, with the exception of the multipart
       bodies.

       A multipart body is either a Mail::Message::Body::Multipart (mime type "multipart/*") or a
       Mail::Message::Body::Nested (mime type "message/rfc822").  These bodies are more complex:

        Mail::Message::Body::Multipart
         |
         `-has-many--Mail::Message::Part
                      |  |
                      |  `-has-one--Mail::Message::Body
                      |
                      `----has-one--Mail::Message::Head

       Before you try to reconstruct multiparts or nested messages yourself, you can better take
       a look at Mail::Message::Construct::Rebuild.

   Message class implementation
       The class structure of messages is very close to that of folders.  For instance, a
       Mail::Box::File::Message relates to a Mail::Box::File folder.

       As extra level of inheritance, it has a Mail::Message, which is a message without
       location.  And there is a special case of message: Mail::Message::Part is a message
       encapsulated in a multipart body.

       The message types are:

        Mail::Box::Mbox::Message            Mail::Box::POP3::Message
        |  Mail::Box::Dbx::Message      Mail::Box::IMAP4::Message  |
        |  |                                                    |  |
        Mail::Box::File::Message             Mail::Box::Net::Message
                |                                      |
                |       Mail::Box::Maildir::Message    |
                |       |   Mail::Box::MH::Message     |
                |       |   |                          |
                |       Mail::Box::Dir::Message        |
                |                |                     |
                `------------.   |   .-----------------'
                             |   |   |
                          Mail::Box::Message    Mail::Message::Part
                                 |                     |
                                 |       .-------------'
                                 |       |
                             Mail::Message
                                 |
                                 |
                           Mail::Reporter (general base class)

       By far most folder features are implemented in Mail::Box, so available to all folder
       types.  Sometimes, features which appear in only some of the folder types are simulated
       for folders that miss them, like sub-folder support for MBOX.

       Two strange other message types are defined: the Mail::Message::Dummy, which fills holes
       in Mail::Box::Thread::Node lists, and a Mail::Box::Message::Destructed, this is an on
       purpose demolished message to reduce memory consumption.

   Labels
       Labels (also named "Flags") are used to indicate some special condition on the message,
       primary targeted on organizational issues: which messages are already read or should be
       deleted.  There is a very strong user relation to labels.

       The main complication is that each folder type has its own way of storing labels.  To give
       an indication: MBOX folders use "Status" and "X-Status" header fields, MH uses a
       ".mh-sequences" file, MAILDIR encodes the flags in the message's filename, and IMAP has
       flags as part of the protocol.

       Besides, some folder types can store labels with user defined names, where other lack that
       feature.  Some folders have case-insensitive labels, other don't. Read all about the
       specifics in the manual page of the message type you actually have.

       Predefined labels

       To standardize the folder types, MailBox has defined the following labels, which can be
       used with the label() and labels() methods on all kinds of messages:

       •   deleted

           This message is flagged to be deleted once the folder closes.  Be very careful about
           the concept of 'delete' in a folder context : it is only a flag, and does not involve
           immediate action!  This means, for instance, that the memory which is used by Perl to
           store the message is not released immediately (see destruct() if you need to).

           The methods delete(), deleted(), and isDeleted() are only short-cuts for managing the
           "delete" label (as of MailBox 2.052).

       •   draft

           The user has prepared this message, but is has not been send (yet).  This flag is not
           automatically added to a message by MailBox, and has only a meaning in user
           applications.

       •   flagged

           Messages can be flagged for some purpose, for instance as result of a search for spam
           in a folder.  The Mail::Box::messages() method can be used to collect all these
           flagged messages from the folder.

           Probably it is more useful to use an understandable name (like "spam") for these
           selections, however these self-defined labels can not stored in all folder types.

       •   old

           The message was already in the folder when it was opened the last time, so was not
           recently added to the folder.  This flag will never automatically be set by MailBox,
           because it would probably conflict with the user's idea of what is old.

       •   passed

           Not often used or kept, this flag indicates that the message was bounced or forwarded
           to someone else.

       •   replied

           The user (or application) has sent a message back to the sender of the message, as
           response of this one.  This flag is automatically set if you use reply(), but not with
           forward() or bounce().

       •   seen

           When this flag is set, the receiver of the message has consumed the message.  A mail
           user agent (MUA) will set this flag when the user has opened the message once.

       Status and X-Status fields

       Mbox folders have no special means of storing information about messages (except the
       message separator line), and therefore have to revert to adding fields to the message
       header when something special comes up.  This feature is also enabled for POP3, although
       whether that works depends on the POP server.

       All applications which can handle mbox folders support the "Status" and "X-Status" field
       convensions.  The following encoding is used:

        Flag   Field       Label
        R      Status   => seen    (Read)
        O      Status   => old     (not recent)
        A      X-Status => replied (Answered)
        F      X-Status => flagged

       There is no special flag for "deleted", which most other folders support: messages flagged
       to be deleted will never be written to a folder file when it is closed.

DIAGNOSTICS

       Error: Cannot coerce a $class object into a $class object
       Error: Cannot include forward source as $include.
           Unknown alternative for the forward(include).  Valid choices are "NO", "INLINE",
           "ATTACH", and "ENCAPSULATE".

       Error: Cannot include reply source as $include.
           Unknown alternative for the "include" option of reply().  Valid choices are "NO",
           "INLINE", and "ATTACH".

       Error: Method bounce requires To, Cc, or Bcc
           The message bounce() method forwards a received message off to someone else without
           modification; you must specified it's new destination.  If you have the urge not to
           specify any destination, you probably are looking for reply(). When you wish to modify
           the content, use forward().

       Error: Method forwardAttach requires a preamble
       Error: Method forwardEncapsulate requires a preamble
       Error: No address to create forwarded to.
           If a forward message is created, a destination address must be specified.

       Error: No default mailer found to send message.
           The message send() mechanism had not enough information to automatically find a mail
           transfer agent to sent this message.  Specify a mailer explicitly using the "via"
           options.

       Error: No rebuild rule $name defined.
       Error: Only build() Mail::Message's; they are not in a folder yet
           You may wish to construct a message to be stored in a some kind of folder, but you
           need to do that in two steps.  First, create a normal Mail::Message, and then add it
           to the folder.  During this Mail::Box::addMessage() process, the message will get
           coerce()-d into the right message type, adding storage information and the like.

       Error: Package $package does not implement $method.
           Fatal error: the specific package (or one of its superclasses) does not implement this
           method where it should. This message means that some other related classes do
           implement this method however the class at hand does not.  Probably you should
           investigate this and probably inform the author of the package.

       Error: coercion starts with some object

SEE ALSO

       This module is part of Mail-Message distribution version 3.006, built on January 24, 2018.
       Website: http://perl.overmeer.net/CPAN/

LICENSE

       Copyrights 2001-2018 by [Mark Overmeer]. For other contributors see ChangeLog.

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.  See http://dev.perl.org/licenses/