diff --git a/ext/curl/gstcurlsmtpsink.c b/ext/curl/gstcurlsmtpsink.c
index 6dbc117469..03f178bdb3 100644
--- a/ext/curl/gstcurlsmtpsink.c
+++ b/ext/curl/gstcurlsmtpsink.c
@@ -918,8 +918,8 @@ gst_curl_smtp_sink_transfer_data_buffer (GstCurlBaseSink * bcsink,
   }
 
   if (sink->base64_chunk != NULL) {
-    if (sink->nbr_attachments_left == sink->nbr_attachments &&
-        bcsink->transfer_buf->len == 0) {
+    if (sink->nbr_attachments_left == sink->nbr_attachments
+        && bcsink->is_live && bcsink->transfer_buf->len == 0) {
       add_final_boundary_unlocked (sink);
     }
     bytes_to_send =