diff --git a/README.md b/README.md
index 4c2bf662..c2505524 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,9 @@ Additional informations:
 - email login are full email address (`username1@my-domain.com`)
 - ssl is strongly recommended
 - do not add whitespace in `$docker_mail_users` or `$docker_mail_aliases`
+- user accounts are managed in `./postfix/accounts.cf`
+- antispam are rules are managed in `./spamassassin/rules.cf`
+- both files must be mounted to `/tmp` in your container (see `docker-compose.yml` template)
 
 ## installation