diff --git a/.gitignore b/.gitignore
index 912337888..f858422d5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,10 +1,12 @@
 rebuild-images.sh
 data/conf/sogo/sieve.creds
 data/conf/dovecot/dovecot-master.passwd
+data/conf/dovecot/dovecot-master.userdb
 mailcow.conf
 mailcow.conf_backup
 data/conf/nginx/*.active
 data/conf/postfix/sql
+data/conf/postfix/allow_mailcow_local.regexp
 data/conf/dovecot/sql
 data/conf/nextcloud-*.bak
 data/web/inc/vars.local.inc.php
diff --git a/data/conf/postfix/master.cf b/data/conf/postfix/master.cf
index 5de97ee09..07d0d8538 100644
--- a/data/conf/postfix/master.cf
+++ b/data/conf/postfix/master.cf
@@ -13,6 +13,8 @@ submission inet n       -       n       -       -       smtpd
 588 inet n      -       n       -       -       smtpd
   -o smtpd_client_restrictions=permit_mynetworks,permit_sasl_authenticated,reject
   -o smtpd_tls_auth_only=no
+  -o smtpd_sender_restrictions=check_sasl_access,regexp:/opt/postfix/conf/allow_mailcow_local.regexp,reject_authenticated_sender_login_mismatch,permit_mynetworks,permit_sasl_authenticated,reject_unlisted_sender,reject_unknown_sender_domain
+
 590 inet n      -       n       -       -       smtpd
   -o smtpd_client_restrictions=permit_mynetworks,reject
   -o smtpd_tls_auth_only=no