diff --git a/caddy/.env.example b/caddy/.env.example
index 0dd206d..684914d 100644
--- a/caddy/.env.example
+++ b/caddy/.env.example
@@ -35,6 +35,8 @@ UPTIME_KUMA_DOMAIN=
 STALWART_DOMAIN=
 STALWART_AUTOCONFIG_DOMAIN=
 STALWART_AUTODISCOVER_DOMAIN=
+STALWART_MTA_STS_DOMAIN=
+STALWART_FREDLENS_MTA_STS_DOMAIN=
 
 ############# Textarea #############
 TEXTAREA_DOMAIN=
diff --git a/caddy/Caddyfile b/caddy/Caddyfile
index 6920907..4e8a7fc 100644
--- a/caddy/Caddyfile
+++ b/caddy/Caddyfile
@@ -205,7 +205,7 @@
 }
 
 ############## stalwart ##############
-{$STALWART_DOMAIN}, {$STALWART_AUTOCONFIG_DOMAIN}, {$STALWART_AUTODISCOVER_DOMAIN} {
+{$STALWART_DOMAIN}, {$STALWART_AUTOCONFIG_DOMAIN}, {$STALWART_AUTODISCOVER_DOMAIN}, {$STALWART_MTA_STS_DOMAIN}, {$STALWART_FREDLENS_MTA_STS_DOMAIN} {
     import access-log
     request_body {
         max_size 4048MB