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Email::Filter.3pm

NAME

Email::Filter - Library for creating easy email filters

SYNOPSIS

     use Email::Filter;
     my $mail = Email::Filter->new(emergency => "~/emergency_mbox");
     $mail->pipe("listgate", "p5p")         if $mail->from =~ /perl5-porters/;
     $mail->accept("perl")                  if $mail->from =~ /perl/;
     $mail->reject("We do not accept spam") if $mail->subject =~ /enlarge/;
     $mail->ignore                          if $mail->subject =~ /boring/i;
     ...
     $mail->exit(0);
     $mail->accept("~/Mail/Archive/backup");
     $mail->exit(1);
     $mail->accept()
 
 

DESCRIPTION

This is another module produced by the ``Perl Email Project'', a reaction against the complexity and increasing bugginess of the ``Mail::*'' modules. It replaces "Mail::Audit", and allows you to write programs describing how your mail should be filtered.

TRIGGERS

Users of "Mail::Audit" will note that this class is much leaner than the one it replaces. For instance, it has no logging; the concept of ``local options'' has gone away, and so on. This is a deliberate design decision to make the class as simple and maintainable as possible.

To make up for this, however, "Email::Filter" contains a trigger mechanism provided by Class::Trigger, to allow you to add your own functionality. You do this by calling the "add_trigger" method:

     Email::Filter->add_trigger( after_accept => \&log_accept );
 
 

Hopefully this will also help subclassers.

The methods below will list which triggers they provide.

ERROR RECOVERY

If something bad happens during the "accept" or "pipe" method, or the "Email::Filter" object gets destroyed without being properly handled, then a fail-safe error recovery process is called. This first checks for the existence of the "emergency" setting, and tries to deliver to that mailbox. If there is no emergency mailbox or that delivery failed, then the program will either exit with a temporary failure error code, queuing the mail for redelivery later, or produce a warning to standard error, depending on the status of the "exit" setting.

METHODS

new

     Email::Filter->new();                # Read from STDIN
     Email::Filter->new(data => $string); # Read from string
 
     Email::Filter->new(emergency => "~simon/urgh");
     # Deliver here in case of error
 
 

This takes an email either from standard input, the usual case when called as a mail filter, or from a string.

You may also provide an ``emergency'' option, which is a filename to deliver the mail to if it couldn't, for some reason, be handled properly.

Hint

If you put your constructor in a "BEGIN" block, like so:

     use Email::Filter;
     BEGIN { $item = Email::Filter->new(emergency => "~simon/urgh"); }
 
 

right at the top of your mail filter script, you'll even be protected from losing mail even in the case of syntax errors in your script. How neat is that?

This method provides the "new" trigger, called once an object is instantiated.

exit

     $mail->exit(1|0);
 
 

Sets or clears the 'exit' flag which determines whether or not the following methods exit after successful completion.

The sense-inverted 'noexit' method is also provided for backwards compatibility with "Mail::Audit", but setting ``noexit'' to ``yes'' got a bit mind-bending after a while.

simple

     $mail->simple();
 
 

Gets and sets the underlying "Email::Simple" object for this filter; see Email::Simple for more details.

header

     $mail->header("X-Something")
 
 

Returns the specified mail headers. In scalar context, returns the first such header; in list context, returns them all.

body

     $mail->body()
 
 

Returns the body text of the email

from

to

cc

bcc

subject

received

     $mail-><header>()
 
 

Convenience accessors for "header($header)"

ignore

Ignores this mail, exiting unconditionally unless "exit" has been set to false.

This method provides the ``ignore'' trigger.

accept

     $mail->accept();
     $mail->accept(@where);
 
 

Accepts the mail into a given mailbox or mailboxes. Unix "~/" and "~user/" prefices are resolved. If no mailbox is given, the default is determined according to Email::LocalDelivery: $ENV{MAIL}, /var/spool/mail/you, /var/mail/you, or ~you/Maildir/.

This provides the "before_accept" and "after_accept" triggers, and exits unless "exit" has been set to false.

reject

     $mail->reject("Go away!");
 
 

This rejects the email; if called in a pipe from a mail transport agent, (such as in a ~/.forward file) the mail will be bounced back to the sender as undeliverable. If a reason is given, this will be included in the bounce.

This calls the "reject" trigger. "exit" has no effect here.

pipe

     $mail->pipe(qw[sendmail foo\@bar.com]);
 
 

Pipes the mail to an external program, returning the standard output from that program if "exit" has been set to false. The program and each of its arguments must be supplied in a list. This allows you to do things like:

     $mail->exit(0);
     $mail->simple(Email::Simple->new($mail->pipe("spamassassin")));
     $mail->exit(1);
 
 

in the absence of decent "Mail::SpamAssassin" support.

If the program returns a non-zero exit code, the behaviour is dependent on the status of the "exit" flag. If this flag is set to true (the default), then "Email::Filter" tries to recover. (See ``ERROR RECOVERY'') If not, nothing is returned.

PERL EMAIL PROJECT

This module is maintained by the Perl Email Project

<http://emailproject.perl.org/wiki/Email::Filter>

COPYRIGHT

     Copyright 2003, Simon Cozens <simon@cpan.org>
 
 

LICENSE

You may use this module under the terms of the BSD, Artistic, or GPL licenses, any version.

AUTHOR

Casey West, "casey@geeknest.com"

Simon Cozens, "simon@cpan.org"