diff --git a/outline/docker-compose.yaml b/outline/docker-compose.yaml
index 2f27405..9f613c4 100644
--- a/outline/docker-compose.yaml
+++ b/outline/docker-compose.yaml
@@ -63,6 +63,13 @@ services:
       - AWS_S3_UPLOAD_MAX_SIZE=26214400
       - AWS_S3_FORCE_PATH_STYLE=true
       - AWS_S3_ACL=private
+      - SMTP_HOST=${SMTP_HOST}
+      - SMTP_PORT=${SMTP_PORT}
+      - SMTP_USERNAME=${SMTP_USER}
+      - SMTP_PASSWORD=${SMTP_PASSWORD}
+      - SMTP_FROM_EMAIL=${SMTP_USER}
+      - SMTP_TLS_CIPHERS=TLSv1.2
+      - SMTP_SECURE=true
       - OIDC_CLIENT_ID=outline
       - OIDC_CLIENT_SECRET=${AUTH_CLIENT_SECRET}
       - OIDC_AUTH_URI=${AUTH_URL}/auth/realms/master/protocol/openid-connect/auth