diff --git a/api/src/Storage/Merge.php b/api/src/Storage/Merge.php
index 831f4acf71..cb4a5e102b 100644
--- a/api/src/Storage/Merge.php
+++ b/api/src/Storage/Merge.php
@@ -2040,6 +2040,10 @@ abstract class Merge
 			}
 			Api\Header\Content::type($header['name'], $header['mime'], $header['filesize']);
 			readfile($result);
+
+			// run egw destructor now explicit, in case a (notification) email is send via Egw::on_shutdown(),
+			// as stream-wrappers used by Horde Smtp fail when PHP is already in destruction
+			$GLOBALS['egw']->__destruct();
 			exit;
 		}