Index: Mail.php
===================================================================
--- Mail.php	(revision 18017)
+++ Mail.php	(working copy)
@@ -98,6 +98,12 @@
     protected $_recipients = array();
 
     /**
+     * Reply-To header
+     * @var string
+     */
+    protected $_replyTo = null;
+    
+    /**
      * Return-Path header
      * @var string
      */
@@ -613,37 +619,78 @@
     }
 
     /**
-     * Set Reply-To Header
+     * Returns the sender of the mail
      *
-     * @param string $email
-     * @param string $name
-     * @return Zend_Mail
+     * @return string
      */
-    public function setReplyTo($email, $name=null)
+    public function getFrom()
     {
-        $this->_addRecipientAndHeader('Reply-To', $email, $name);
+        return $this->_from;
+    }
+
+    /**
+     * Clears the sender from the mail
+     *
+     * @return Zend_Mail Provides fluent interface
+     */
+    public function clearFrom()
+    {
+        $this->_from = null;
+        $this->_clearHeader('From');
+
         return $this;
     }
 
     /**
-     * Returns the sender of the mail
+     * Sets Reply-To header of the message
      *
+     * @param  string    $email
+     * @param  string    $name
+     * @return Zend_Mail Provides fluent interface
+     * @throws Zend_Mail_Exception if called subsequent times
+     */
+    public function setReplyTo($email, $name = null)
+    {
+        if ($this->_replyTo === null) {
+            $email = $this->_filterEmail($email);
+            $name  = $this->_filterName($name);
+            $this->_replyTo = $email;
+            $this->_storeHeader('Reply-To', $this->_formatAddress($email, $name), true);
+        } else {
+            /**
+             * @see Zend_Mail_Exception
+             */
+            require_once 'Zend/Mail/Exception.php';
+            throw new Zend_Mail_Exception('Reply-To Header set twice');
+        }
+        return $this;
+    }
+
+    /**
+     * Returns the current Reply-To address of the message
+     *
+     * If no Reply-To header is set, returns the value of {@link $_from}.
+     *
      * @return string
      */
-    public function getFrom()
+    public function getReplyTo()
     {
+        if (null !== $this->_replyTo) {
+            return $this->_replyTo;
+        }
+
         return $this->_from;
     }
 
     /**
-     * Clears the sender from the mail
+     * Clears the current Reply-To address from the message
      *
      * @return Zend_Mail Provides fluent interface
      */
-    public function clearFrom()
+    public function clearReplyTo()
     {
-        $this->_from = null;
-        $this->_clearHeader('From');
+        $this->_replyTo = null;
+        $this->_clearHeader('Reply-To');
 
         return $this;
     }