diff --git a/postfixinstall b/postfixinstall
index 1233132..ebbb4f4 100755
--- a/postfixinstall
+++ b/postfixinstall
@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
+# SPDX-License-Identifier: MIT
 
 # Author        : Allan Christensen
 # First Created : 17102020 (DD-MM-YYYY)