diff --git a/upload-diffs.py b/upload-diffs.py
index 1b5daac..c3ff6b9 100644
--- a/upload-diffs.py
+++ b/upload-diffs.py
@@ -487,7 +487,7 @@
                  help="Base revision/branch/tree to diff against. Use "
                       "rev1:rev2 range to review already committed changeset.")
 group.add_option("--send_mail", action="store_true",
-                 dest="send_mail", default=False,
+                 dest="send_mail", default=True,
                  help="Send notification email to reviewers.")
 group.add_option("--vcs", action="store", dest="vcs",
                  metavar="VCS", default=None,