#!/usr/bin/env perl 
use strict;
use warnings;
use Email::MIME;
use Encode;

my $raw = <<'EOT';
Subject:
=?UTF8?B?5LuO5Y2a5a6i5paH56ug5Lit5p+l5om+5oKo5oSf5YW06Laj55qE5Li7?==?UTF-8?B?6aKY?=
=?UTF8?B?it5p+l5om+5oKo5oSf5YW06Laj55?=
To: larry@perl.org
From: peteredhair@perlmonks.org

Hi Larry!
EOT
my $email = Email::MIME->new ($raw);

# Just one
my $subj = $email->header ('Subject');
print "Single header subject is '", encode ("utf-8", $subj), "'\n\n";

# Or all of them
my @headers = $email->header_str_pairs ();
while (@headers) {
    my $key = shift @headers;
    my $val = shift @headers;
    print "$key: ", encode ("utf-8", $val), "\n";
}