Fixed PHP error with bounce processor on empty IMAP mailbox

[Mike]

Some IMAP servers may cause an error when processing bounced emails and the mailbox is empty. Note that when there is mail in the mailbox, it is still collected and processed correctly. This fix just prevents your error log from being filled spuriously.

In library/Zend/Mail/Protocol/Imap.php, add the code in red:

           $response = $this->requestAndResponse('SEARCH', $params); 
           if (!$response) { 
               return $response; 
           } 
           if ($response === true) { 
               // returned no entries 
               return array(); 
           }