diff --git a/.env.example b/.env.example
index 08b7ea09..fea2feea 100644
--- a/.env.example
+++ b/.env.example
@@ -67,6 +67,17 @@ JMAP_SERVER_URL=https://your-jmap-server.com
 # For Docker, mount a persistent volume at this path.
 # SETTINGS_DATA_DIR=./data/settings
 
+# =============================================================================
+# Server Listen Address
+# =============================================================================
+
+# Hostname the server binds to (default: 0.0.0.0)
+# Set to "::" for IPv6 or "[::]" for dual-stack support.
+# HOSTNAME=0.0.0.0
+
+# Port the server listens on (default: 3000)
+# PORT=3000
+
 # =============================================================================
 # Logging
 # =============================================================================
diff --git a/README.md b/README.md
index 7931c4b7..53fc5600 100644
--- a/README.md
+++ b/README.md
@@ -243,6 +243,16 @@ APP_NAME=My Webmail
 
 All variables are **runtime** — Docker deployments can be configured without rebuilding.
 
+<details>
+<summary>Server Listen Address</summary>
+
+```env
+HOSTNAME=0.0.0.0    # Default; use "::" for IPv6
+PORT=3000            # Default listen port
+```
+
+</details>
+
 <details>
 <summary>OAuth2/OIDC (SSO)</summary>
 
diff --git a/docker-compose.yml b/docker-compose.yml
index 733c3645..a228a0ae 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -3,6 +3,9 @@ services:
     image: ghcr.io/bulwarkmail/webmail:latest
     ports:
       - "3000:3000"
+    environment:
+      - HOSTNAME=0.0.0.0     # Use "::" for IPv6
+      - PORT=3000
     env_file:
       - .env.local
     healthcheck: