diff --git a/ImapClient/IncomingMessage.php b/ImapClient/IncomingMessage.php
index <HASH>..<HASH> 100644
--- a/ImapClient/IncomingMessage.php
+++ b/ImapClient/IncomingMessage.php
@@ -387,7 +387,14 @@ class IncomingMessage
             }
         }
         if (isset($objNew->plain)) {
-            $objNew->text = quoted_printable_decode( mb_convert_encoding( $objNew->plain, "utf-8", $objNew->plain->charset ));
+            switch ($objNew->plain->structure->encoding) {
+                case 3:
+                    $objNew->text = imap_base64(mb_convert_encoding( $objNew->plain, "utf-8", $objNew->plain->charset ));
+                    break;
+                default:
+                    $objNew->text = quoted_printable_decode(mb_convert_encoding( $objNew->plain, "utf-8", $objNew->plain->charset ));
+                    break;
+            }
             $objNew->types[] = 'text';
         } else {
             $objNew->text = null;
Added support for base<I> encoded mail