diff --git a/lib/Cake/Network/Email/CakeEmail.php b/lib/Cake/Network/Email/CakeEmail.php
index bc36301cb..bc5b821a7 100644
--- a/lib/Cake/Network/Email/CakeEmail.php
+++ b/lib/Cake/Network/Email/CakeEmail.php
@@ -1240,9 +1240,14 @@ class CakeEmail {
 /**
  * Attach non-embedded files by adding file contents inside boundaries.
  *
+ * @param string $boundary Boundary to use. If null, will default to $this->_boundary 
  * @return array An array of lines to add to the message
  */
-	protected function _attachFiles() {
+	protected function _attachFiles($boundary = null) {
+		if ($boundary === null) {
+			$boundary = $this->_boundary;
+		}
+
 		$msg = array();
 		foreach ($this->_attachments as $filename => $fileInfo) {
 			if (!empty($fileInfo['contentId'])) {
@@ -1250,7 +1255,7 @@ class CakeEmail {
 			}
 			$data = $this->_readFile($fileInfo['file']);
 
-			$msg[] = '--' . $this->_boundary;
+			$msg[] = '--' . $boundary;
 			$msg[] = 'Content-Type: ' . $fileInfo['mimetype'];
 			$msg[] = 'Content-Transfer-Encoding: base64';
 			$msg[] = 'Content-Disposition: attachment; filename="' . $filename . '"';
@@ -1278,9 +1283,14 @@ class CakeEmail {
 /**
  * Attach inline/embedded files to the message.
  *
+ * @param string $boundary Boundary to use. If null, will default to $this->_boundary 
  * @return array An array of lines to add to the message
  */
-	protected function _attachInlineFiles() {
+	protected function _attachInlineFiles($boundary = null) {
+		if ($boundary === null) {
+			$boundary = $this->_boundary;
+		}
+
 		$msg = array();
 		foreach ($this->_attachments as $filename => $fileInfo) {
 			if (empty($fileInfo['contentId'])) {
@@ -1288,7 +1298,7 @@ class CakeEmail {
 			}
 			$data = $this->_readFile($fileInfo['file']);
 
-			$msg[] = '--rel-' . $this->_boundary;
+			$msg[] = '--' . $boundary;
 			$msg[] = 'Content-Type: ' . $fileInfo['mimetype'];
 			$msg[] = 'Content-Transfer-Encoding: base64';
 			$msg[] = 'Content-ID: <' . $fileInfo['contentId'] . '>';
@@ -1365,7 +1375,7 @@ class CakeEmail {
 		}
 
 		if ($hasInlineAttachments) {
-			$attachments = $this->_attachInlineFiles();
+			$attachments = $this->_attachInlineFiles($relBoundary);
 			$msg = array_merge($msg, $attachments);
 			$msg[] = '';
 			$msg[] = '--' . $relBoundary . '--';
@@ -1373,7 +1383,7 @@ class CakeEmail {
 		}
 
 		if ($hasAttachments) {
-			$attachments = $this->_attachFiles();
+			$attachments = $this->_attachFiles($boundary);
 			$msg = array_merge($msg, $attachments);
 		}
 		if ($hasAttachments || $hasMultipleTypes) {