You could try using in conjuction with Expect;

#!/usr/bin/perl
use strict;
use warnings;
use Net::OpenSSH;
use Expect;

select STDOUT; $| = 1;
select STDERR; $| = 1;
my $timeout  = 5;
my $password = '';
my $user     = '';
my $host     = '';

my $ssh = Net::OpenSSH->new(host=>$host, 
                            user=>$user,
                        password=>$password);

my ($pty, $pid) = $ssh->open2pty("sudo -k; sudo su - imail -c ls")
    or die "open2pty failed: " . $ssh->error . "\n";

my $expect = Expect->init($pty);
$expect->raw_pty(1);
$expect->expect($timeout, ':')
    or die "expect failed\n";
$expect->send("$password\n");
$expect->expect($timeout, "\n")
    or die "bad password\n";

while(<$pty>) {
  print "$. $_"
}
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