$msg->sender bug? Or bad usage?

I have a script that catches bounces from a mailing list. Some of the 
bounces are very, very odd which tend to tickle bugs in my code.

The relevant chunks of my code are:

my $msg = Mail::Message->read(\*STDIN);
my @from = ();

print "Before\n";
print "\$#from is: $#from\n";
print "\$from is: $from[0]\n";
print "Scalar: ",scalar(@from),"\n";

@from = $msg->sender;

print "After\n";
print "\$#from is: $#from\n";
print "\$from is: $from[0]\n";
print "Scalar: ",scalar(@from),"\n";

my @from_address_list = ();
if ($#from >= 0) {
         foreach (@from) {
                 push (@from_address_list, $_->address);
         }
}

Here is one of the emails that caused the error:

Received: from msnmail2.uswest.net (msnmail2.uswest.net 
[::ffff:63.226.138.22])
   by hambone.com with esmtp; Sun, 18 Jan 2004 12:03:51 -0700
Received: (qmail 57512 invoked by uid 0); 18 Jan 2004 18:30:44 -0000
Received: from unknown (63.226.138.9)
   by msnmail2.uswest.net with QMQP; 18 Jan 2004 18:30:44 -0000
Delivered-To: [email protected]
To: [email protected]
Subject: Re: Harvesting cilantro
References: <[email protected]>
In-Reply-To: <[email protected]>
Message-ID: <[email protected]>
Date: Sun, 18 Jan 2004 12:03:51 -0700

The email address for [email protected] has changed.  Please send all
future correspondence to [email protected].

And when I run "cat badmail | testscript.pl" , I get:

Before
$#from is: -1
Use of uninitialized value in concatenation (.) or string at 
./testscript.pl line 5, <STDIN> line 1.
$from is:
Scalar: 0
After
$#from is: 0
Use of uninitialized value in concatenation (.) or string at 
./testscript.pl line 11, <STDIN> line 1.
$from is:
Scalar: 1
Can't call method "address" on an undefined value at ./testscript.pl 
line 17, <STDIN> line 1.

My understanding is that if an array is empty then $#array should be -1. 
It seems to me that @from = $msg->sender; seems to be doing something 
very strange to @from, making all values none-existent, but changing the 
index.

Maybe my perl isn't strong enough here, but that seems not right to me.

What am I missing?

Adam Augustine