$ ls -l /var/mail/alias/arch -rw-r--r-- 1 root archalias 48 Mar 11 17:40 alpha -rw-r--r-- 1 root root 493 Mar 11 17:34 ppc -rw-r--r-- 1 root root 8 Mar 11 17:34 ppc-macos Should all be root:archalias and rw-rw-r--.
fixed.