use Win32::OLE;
use Win32::OLE::Variant;
use Win32::OLE::Const 'Microsoft Outlook';
my $Outlook = Win32::OLE->GetActiveObject('Outlook.Application');
my $ol = Win32::OLE::Const->Load($Outlook);
my $namespace = $Outlook->GetNamespace("MAPI");
my $Folder = $namespace->Folders('mymail')->Folders('Inbox');
my $n = $Folder->Items->Count;
for ($i=$n; $i>0; $i--) {
    my $msg = $Folder->Items($i);
    my $to = $msg->{'To'};
}