diff --git a/template/yoga/mail/text/plain/header.tpl b/template/yoga/mail/text/plain/header.tpl
index d409439bc..1aefc7d2d 100644
--- a/template/yoga/mail/text/plain/header.tpl
+++ b/template/yoga/mail/text/plain/header.tpl
@@ -1,3 +1,3 @@
 -----={BOUNDARY_KEY}
-Content-Type: {CONTENT_TYPE}; charset={CONTENT_ENCODING}; format=flowed;
+Content-Type: {CONTENT_TYPE}; charset={CONTENT_ENCODING};
 Content-Transfer-Encoding: 8bit