Sending Email in Modern Perl

In earlier Perl versions, scripts often relied on piping output to a Unix utility such as sendmail to send messages. While that method worked, it required direct access to the system’s mail transfer agent and lacked portability across platforms. Today, modern Perl provides robust, secure, and platform-independent ways to send email using dedicated modules such as Email::Stuffer, Email::Sender, or MIME::Lite.

Legacy Approach Using sendmail

Before Perl’s mail libraries became common, developers would open a pipe to sendmail and manually construct headers and message content. Although educational, this method is rarely used today due to security and maintainability issues.

#!/usr/bin/perl
use strict;
use warnings;

my $sendmail = "/usr/sbin/sendmail -t";
my $from     = "yourname@example.com";
my $to       = "recipient@example.com";
my $subject  = "Legacy Email Example";

open(my $mail, "|$sendmail") or die "Cannot open sendmail: $!";
print $mail <<"MESSAGE";
From: $from
To: $to
Subject: $subject

This is a legacy method for sending email through sendmail.
MESSAGE
close($mail);

This example demonstrates how Perl scripts traditionally interacted with the mail transfer agent through pipes. Headers such as From, To, and Subject must appear before a blank line separating them from the message body. The approach works but can be prone to injection vulnerabilities and lacks encoding support for attachments or HTML content.

Modern Perl Email Example

Today, the preferred way to send emails in Perl is through modules available on CPAN that abstract away the lower-level details of SMTP communication. The Email::Stuffer module provides a clean, object-oriented interface for creating and sending messages.

#!/usr/bin/perl
use strict;
use warnings;
use Email::Stuffer;

Email::Stuffer->from('yourname@example.com')
              ->to('recipient@example.com')
              ->cc('manager@example.com')
              ->subject('Perl Email Example')
              ->text_body('This email was sent using Email::Stuffer.')
              ->send or die "Failed to send email: $!";

This modern method automatically handles encoding, headers, and SMTP communication. It also supports attachments, HTML bodies, and external mail servers, making it ideal for production systems.

Understanding Email Headers

An Internet email message consists of standardized headers followed by the body. The headers provide metadata about the sender, recipient, and routing. Although many are automatically handled by mail libraries, you may still need to define or inspect key ones:

To:        Recipient’s email address
From:      Sender’s email address
Reply-To:  Address for replies
Cc:        Additional recipients (carbon copy)
Bcc:       Hidden recipients (blind carbon copy)
Subject:   Topic of the message
X-* :      Custom headers for logging or filtering

Headers beginning with X- are user-defined and can be used for automation, message tracking, or custom mail filters. For instance, X-App-ID: FormMailer might help identify emails originating from a specific web application.

Practical Considerations

When deploying Perl-based email features:

• Use Email::Stuffer or Email::Sender for modern reliability.
• Configure authentication properly for your SMTP server.
• Validate all input fields to prevent header injection.
• Use UTF-8 encoding to ensure compatibility across languages.

In the next lesson, you’ll build a web form that allows users to send messages through a Perl backend, combining form validation with secure email delivery.