Processing a Mailbox With POP and Perl

My company sends out newsletters. Of course, for whatever reason sometimes a user no longer wishes to receive these newsletters; and sometimes a user will continue to receive newsletters and instead of using the "unsubscribe" links in the newsletter, they will just mark the email as junk. So, then their ISP, email provider, etc. will then do their job to send us an email saying that there has been a complaint about us spamming. The routine continues and the emails go round and round.

Here is where our "Auto Unsubscribe" mailbox comes to play. We have a mailbox setup where email providers forward emails of complaints. They pretty much always keep the original email message intact, so the auto unsubscribe job is easy: search through the mailbox for the data you need; the unsubscriber's email address and the newsletter.

Finding the correct data is simple on our end as long as the original newsletter email is intact. At the bottom of all of our newsletters is a link to an unsubscribe page. Now, in plain text this is obviously just going to be a line with a URI and parameters. For example, http://www.server.com/unsubscribe.htm?newsletter=ABC&e=youremail@mail.com

You see where I'm going here? You've got all the data you need and now you can do what you want with it.

Cheers!

NOTE: I'm using the Mail::POP3Client module because I personally needed to use SSL when connecting to the mailbox. You can easily use Net::POP3, Net::IMAP, etc. just the same.


#!/usr/bin/perl
#
# unsub-pop.pl v1.0
# Adrian J. Cruz
# 2009-02-19

use strict;
use Mail::POP3Client;

my $mail_server = qw(mail.server.com);
my $mail_user = qw(user@server.com);
my $mail_pass = qw(pass123);
my $pop = new Mail::POP3Client( USER => $mail_user,
PASSWORD => $mail_pass,
HOST => $mail_server,
USESSL => "true");
$pop->Connect
or die "couldn't connect: $!\n";

# find newsletter and email
my @ecunsubs;
for (my $i = 1; $i <= $pop->Count(); $i++) {
foreach ($pop->Body($i)) {
if (/unsubscribe\.htm\?newsletter\=(.+\&e\=.+)\"/) {
push(@ecunsubs,$1);
}
}
# mark msg to be deleted
$pop->Delete($i);
}
$pop->Close;

# remove duplicates so now we process only unique entries
my %sorthash;
@sorthash{@ecunsubs} = ();
my @unsubs = keys %sorthash;
...
...
etc.
...