diff --git a/README.md b/README.md
index 45649f1..7f795f1 100644
--- a/README.md
+++ b/README.md
@@ -2,3 +2,9 @@
 
 see forum https://forum.howtoforge.com/threads/postfix-dovecot-sni-for-letsencrypt-certificates-via-cron-script-auto.86878/
 
+
+in postfix main.cf:
+tls_server_sni_maps = ${indexed}sni
+
+in dovecot 99-ispconfig-custom-config.conf:
+!include_try /etc/dovecot/sni.conf