diff --git a/core/postfix/conf/master.cf b/core/postfix/conf/master.cf
index eca0ad77..15613476 100644
--- a/core/postfix/conf/master.cf
+++ b/core/postfix/conf/master.cf
@@ -7,6 +7,7 @@ smtp      inet  n       -       n       -       -       smtpd
 # Internal SMTP service
 10025     inet  n       -       n       -       -       smtpd
   -o smtpd_sasl_auth_enable=yes
+  -o smtpd_discard_ehlo_keywords=pipelining
   -o smtpd_client_restrictions=$check_ratelimit,reject_unlisted_sender,reject_authenticated_sender_login_mismatch,permit
   -o smtpd_reject_unlisted_recipient={% if REJECT_UNLISTED_RECIPIENT %}{{ REJECT_UNLISTED_RECIPIENT }}{% else %}no{% endif %}
   -o cleanup_service_name=outclean