the server show this issue in mailq
[root@server ~]# mailq
-Queue ID- --Size-- ----Arrival Time---- -Sender/Recipient-------
9A3481E0D9F 8679 Thu Apr 16 17:08:15 mail@domain.net
(mail system configuration error)
mail2@domain.net
mail3@domain.net
var log maillog
Apr 17 00:10:18 server postfix/pipe[11668]: warning: pipe flag `D' requires dovecot_destination_recipient_limit = 1
i cant find dovecot_destination_recipient_limit = 1 in main.cf or master.cf