Perl in a Nutshell, 2nd Edition

Better Header Control with Mail::Send

Mail::Send is built on top of Mail::Mailer, which means that you can also choose the mail program that sends the mail. Mail::Send has implemented the methods to, cc, bcc, and subject to replace the %headers hash used in Mail::Mailer.

Mail::Send uses the open method to open the mail program for output; it is built on Mail::Mailer’s new method, so that:

# Start mailer and output headers
$fh = $msg->open('sendmail');

serves the same purpose as:

# Use sendmail for mailing
$mailer = Mail::Mailer->new('sendmail)';

This code tells Mail::Send to use sendmail as the mail program.

Mail::Send also provides the set and add functions, which assign a value to a header tag and append a value to a header tag, respectively. The set function takes two arguments—a header tag and a value—and is used like this:

$msg->set($scalar, @array);

Therefore, to address a message to [e-mail]:

$msg->set('To', '[e-mail]');

The above sets the To header to [e-mail]; however, the following sets the To header to [e-mail] and [e-mail] because they represent an array of values:

$msg->set('To', ('[e-mail]', '[e-mail]'));

You might think that you could use the set function as follows to add multiple values to a header value:

$msg->set('To', '[e-mail]');
$msg->set('To', '[e-mail]');

However, set doesn’t append information from one call to another, and the above ...