diff --git a/README.md b/README.md
index 6ab4af3..45649f1 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,4 @@
 # ispconfig-sni
 
+see forum https://forum.howtoforge.com/threads/postfix-dovecot-sni-for-letsencrypt-certificates-via-cron-script-auto.86878/
+