diff --git a/src/administration/configuration.md b/src/administration/configuration.md
index 10ed8c6..9f7d86d 100644
--- a/src/administration/configuration.md
+++ b/src/administration/configuration.md
@@ -2,7 +2,12 @@
 
 The configuration is based on the file config.hjson, which is located by default at `config/config.hjson`. To change the default location, you can set the environment variable `LEMMY_CONFIG_LOCATION`.
 
-An additional environment variable `LEMMY_DATABASE_URL` is available, which can be used with a PostgreSQL connection string like `postgres://lemmy:password@lemmy_db:5432/lemmy`, passing all connection details at once.
+Additional environment variable are available:
+
+- `LEMMY_DATABASE_URL`, which can be used with a PostgreSQL connection string like `postgres://lemmy:password@lemmy_db:5432/lemmy`, passing all connection details at once,
+- `LEMMY_SMTP_PASSWORD`, which can be used to set the password to authenticate with the SMTP server.
+
+Those environment variables will override values if specified in the config file.
 
 If the Docker container is not used, manually create the database specified above by running the following commands: