[Postfix] – warning: mail_queue_enter: create file maildrop Permission denied

After trying to setup postgrey, I had a lot of warning messages in my mail.log file like this: May 7 12:26:19 gandalf postfix/postdrop[6065]: warning: mail_queue_enter: create file maildrop/713410.6065: Permission denied May 7 12:26:29 gandalf postfix/postdrop[6119]: warning: mail_queue_enter: create file maildrop/724102.6119: Permission denied May 7 12:26:29 gandalf postfix/postdrop[6065]: warning: mail_queue_enter: create file maildrop/734104.6065: Permission denied May […]