connect imap server to clenaup unwanted emails

exchange_cleanup.pl

#!/usr/bin/perl
use strict;
use warnings;
use Net::IMAP::Simple;
use Encode qw/encode decode/; 

my $host = 'imap.server.com'
my $login = 'carlo.caputo';
my $password = '123456';
my $delete_pattern = 'Undeliverable: (maillist|useless|automatic)';

my $debug = 1;

my $n;
my $server = new Net::IMAP::Simple($host) or die  $Net::IMAP::Simple::errstr;
$server->login($login, $password)  or die  $server->errstr;
print "remove undesirable email...\n" if $debug;
for my $box (qw(INBOX INBOX/assignment)) {
	print "select $box...\n" if $debug;
	defined($n = $server->select($box)) or die  $server->errstr;
	while ($n) {
		print "header $box ($n)...\n" if $debug > 1;
		my $header = $server->top($n) or warn $server->errstr; 
		@_ = map {s/\r$//;$_} @{$header};
		while(@_) {
			$_ = shift @_; s/[\n\r]+$//; print "| $_\n" if $debug > 2;
			if(/: /) {
				my ($field, $data) = ($`,$');
				if($field =~ /^Subject/i) {
					$_ = $data;
					if(/^=\?[^\?]+\?[BQ]\?/) {
						$data = '';
						for(;;) {
							$data .= decode('MIME-Header', $_);
							last unless $_[0] =~ s/^\t//;
							$_ = shift @_; s/[\n\r]+$//; print "+ $_\n" if $debug > 2;
						}
						$_ = $data;
					}
					print "$n) $_\n" if $debug > 2; 
					if(/$delete_pattern/) {
						print " ^^^^^\n" if $debug > 2;
						$server->delete($n) or warn $server->errstr;
					}
					print "\n" if $debug > 2;
					last;
				}
			}
		}
		$n--;
	}
}
print "expunge inbox...\n" if $debug;
$server->expunge_mailbox('INBOX/assignment') or die  $server->errstr;
$server->expunge_mailbox('INBOX')            or die  $server->errstr;

for my $box ('Deleted Items', 'Spam', 'Trash') {
	print "delete $box...\n" if $debug;
	defined($n = $server->select($box)) or die  $server->errstr;
	foreach (1..$n) {
		$server->delete($_) or warn $server->errstr; 
	}
	print "expunge $box...\n" if $debug;
	$server->expunge_mailbox($box)    or die  $server->errstr;
}

print "quit...\n" if $debug;
$server->quit() or warn $server->errstr;