For a non-root user, postdrop fails with "warning: mail_queue_enter: create file maildrop/###.###: Permission denied" where, ###.### is some number. The reason is that postfix isn't installed with setgid (install.cf), so postdrop runs with the permissions of the user who runs it (postdrop is called by postfix's sendmail replacement, which is called by mail programs like mutt). But /var/spool/postfix/maildrop is installed with user/group postfix/postdrop and isn't world-writable. Postdrop needs to write to that directory, so if setgid isn't set in the postfix install/build, which appears to not be, /var/spool/postfix/maildrop should be world-writable (the Mandrake postfix install does this). However, the better answer is to set setgid on the postfix install. The URL above has more info: Scroll down to "Protecting your maildrop directory".
latest postfix fixes this problem .. thanks woodchip :)
