my $imap = Mail::IMAPClient->new( 
   Socket   => $socket, 
   User     => $Username, 
   Password => $Password 
  ) 
  or die "new(): $@"; 
 
$imap->select($folder) or die "Could not select: $@"; 
my @uids = $imap->search('SUBJECT', $subject_string) or die "Could not find messages with subject: $@\n";

##</code><code>##

my @uids = $imap->search(SUBJECT => "$subject_string", DATE => "Feb 1, 20101") or die "Could not find messages with subject: $@\n";