diff --git a/.envrc.sample b/.envrc.sample
index a1fd65b..793ac84 100644
--- a/.envrc.sample
+++ b/.envrc.sample
@@ -5,3 +5,10 @@ export LETS_ENCRYPT_ENV=production
 export DB_ROOT_PASSWORD_VERSION=v1
 export DB_PASSWORD_VERSION=v1
 export ADMIN_PASSWORD_VERSION=v1
+
+## SMTP settings
+#export COMPOSE_FILE="compose.yml:compose.mailrelay.yml"
+#export SMTP_HOST="postfix_relay_app"
+## Emails are sent from $MAIL_FROM@$MAIL_DOMAIN
+#export MAIL_DOMAIN=b0x.f0x.link
+#export MAIL_FROM_ADDRESS=nextcloud
diff --git a/compose.mailrelay.yml b/compose.mailrelay.yml
new file mode 100644
index 0000000..c49968d
--- /dev/null
+++ b/compose.mailrelay.yml
@@ -0,0 +1,15 @@
+version: "3.8"
+ 
+services:
+  app:
+    environment:
+      - SMTP_HOST
+      - MAIL_FROM_ADDRESS
+      - MAIL_DOMAIN
+      - SMTP_AUTHTYPE=PLAIN
+    networks:
+      - mail
+
+networks:
+  mail:
+    external: true