diff --git a/start.sh b/start.sh
index bee3f83..27e684b 100644
--- a/start.sh
+++ b/start.sh
@@ -42,6 +42,19 @@ https://bw.{\$NC_DOMAIN}:443 {
 CADDY
 fi
 
+if [ -n "$(dig A +short nextcloud-aio-stalwart)" ] && ! grep -q "mail.$NC_DOMAIN" /Caddyfile; then
+    cat << CADDY >> /Caddyfile
+https://mail.{\$NC_DOMAIN}:443 {
+    # TLS options
+    tls {
+        issuer acme {
+            disable_http_challenge
+        }
+    }
+}
+CADDY
+fi
+
 mkdir -p /data/caddy-imports
 if ! grep -q "/data/caddy-imports" /Caddyfile; then
     echo 'import /data/caddy-imports/*' >> /Caddyfile