diff --git a/compose.mailrelay.yml b/compose.mailrelay.yml
new file mode 100644
index 0000000..553286b
--- /dev/null
+++ b/compose.mailrelay.yml
@@ -0,0 +1,13 @@
+---
+version: "3.8"
+
+services:
+  app:
+    environment:
+      - SMTP_HOST=${SMTP_HOST}
+    networks:
+      - mail
+
+networks:
+  mail:
+    external: true