Merge pull request #451 in ZP/z-push from...

Merge pull request #451 in ZP/z-push from bugfix/ZP-1143-strict-standards-message-when-sending to develop

* commit '25278dd6':
  ZP-1143 Strict Standards message when sending an email using IMAP backend.

src/backend/imap/imap.php

@@ -2461,7 +2461,7 @@ class BackendIMAP extends BackendDiff implements ISearchProvider {
         }
 
         ZLog::Write(LOGLEVEL_DEBUG, sprintf("BackendIMAP->sendMessage(): SendingMail with %s", $sendingMethod));
-        $mail =& Mail::factory($sendingMethod, $sendingMethod == "mail" ? "-f " . $fromaddr : $imap_smtp_params);
+        $mail = Mail::factory($sendingMethod, $sendingMethod == "mail" ? "-f " . $fromaddr : $imap_smtp_params);
         $send = $mail->send($recipients, $headers, $body);
         ZLog::Write(LOGLEVEL_DEBUG, sprintf("BackendIMAP->sendMessage(): send return value %s", $send));