diff --git a/tools/import-mbox.py b/tools/import-mbox.py
index e2f94f0..95ceb8c 100755
--- a/tools/import-mbox.py
+++ b/tools/import-mbox.py
@@ -289,7 +289,7 @@
                     jas.append(json_source)
                     if args.verbose:
                         # TODO optionally show other fields (e.g. From_ line)
-                        print("%(mid)s %(message-id)s" % json)
+                        print("MID:%(mid)s MSGID:%(message-id)s" % json)
                     if contents:
                         if not args.dry:
                             for key in contents: