gistfile1.diff

diff --git a/lib/Cake/Network/Email/SmtpTransport.php b/lib/Cake/Network/Email/SmtpTransport.php
index 363e477..ec48d6c 100644
--- a/lib/Cake/Network/Email/SmtpTransport.php
+++ b/lib/Cake/Network/Email/SmtpTransport.php
@@ -145,7 +145,10 @@ class SmtpTransport extends AbstractTransport {
  * @throws SocketException
  */
   protected function _sendRcpt() {
-		$from = $this->_cakeEmail->from();
+		$from = $this->_cakeEmail->returnPath();
+		if (empty($from)) {
+			$from = $this->_cakeEmail->from();
+		}
 		$this->_smtpSend('MAIL FROM:<' . key($from) . '>');
 
 		$to = $this->_cakeEmail->to();