#!/usr/bin/perl

use feature qw/say/;
use warnings;
use strict;

use Encode;
#assuming that my message is stored in some variable called $str
my $str="Wir freuen uns, dass Sie den 1&1 E-Mail-Service f=C3=BCr Ihre=20";

print decode('MIME-Header', "Wir freuen uns, dass Sie den 1&1 E-Mail-Service f=C3=BCr Ihre=20");
print "\n";
print decode('MIME-Header', "=?iso-8859-1?Q?".$str);