diff --git a/postfix/conf/master.cf b/postfix/conf/master.cf
index c0f68233..d64645a1 100644
--- a/postfix/conf/master.cf
+++ b/postfix/conf/master.cf
@@ -6,6 +6,7 @@ smtp      inet  n       -       n       -       -       smtpd
 
 # Internal SMTP service
 10025     inet  n       -       n       -       -       smtpd
+  -o smtpd_sasl_auth_enable=yes
   -o smtpd_recipient_restrictions=reject_unlisted_sender,reject_sender_login_mismatch,permit
   -o cleanup_service_name=outclean
 outclean  unix n       -       n       -       0       cleanup