diff --git a/start.sh b/start.sh
index 4248c2d..d60e5c0 100755
--- a/start.sh
+++ b/start.sh
@@ -797,6 +797,34 @@ customize_mail_templates() {
 {{end}}
 EOF_BASE_TEMPLATE
   chown cloudron:cloudron "$base_template"
+
+  python3 - "$MUSEUM_RUNTIME_DIR/mail-templates" "$BASE_URL" <<'PY'
+import re
+import sys
+from pathlib import Path
+
+template_dir = Path(sys.argv[1])
+base_url = sys.argv[2]
+
+footer_html = f'''
+    <div class="footer" style="text-align: center; font-size: 12px; color: #888; padding: 16px;">
+      <p style="margin-bottom: 4px;">
+        <strong><a href="{base_url}" target="_blank" style="color: #555;">{base_url}</a></strong>
+      </p>
+      <p style="margin: 0;">This email was sent by a self-hosted instance of the open source Ente application.</p>
+    </div>
+  </body>'''.lstrip()
+
+pattern = re.compile(r'<div class="footer".*?</div>\s*</body>', re.DOTALL | re.IGNORECASE)
+
+for html_path in template_dir.rglob("*.html"):
+    original = html_path.read_text()
+    updated = pattern.sub(footer_html, original)
+    if updated != original:
+        html_path.write_text(updated)
+        # Ownership will be fixed later by the caller
+PY
+  find "$MUSEUM_RUNTIME_DIR/mail-templates" -type f -name "*.html" -exec chown cloudron:cloudron {} +
 }
 
 customize_mail_templates