Postfix Aliases and Server Setup

[new_linux_fans_jack]

To All Postfix Guru,

I am really new to Linux, not to say Postfix. Currently, I need to setup a postfix server for a project, and have some of the problems below, please help:

I coudn't find the aliases.db under /etc/postfix. From the maillog, there is an entry "Oct 16 16.52.50 mail postfix/postalias[2390]: fatal: open /etc/postfix/aliases: No such file or directory". I wonder am I missing any steps while installing the Postfix server to create such aliases.db file.

this is my postfix -n:
alias_database = hash:/etc/postfix/aliases
alias_maps = hash:/etc/postfix/aliases
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
debug_peer_level = 2
home_mailbox = Maildir/
html_directory = no
inet_interfaces = all
mail_owner = postfix
mailbox_command = /user/bin/procmail -a "$DOMAIN"
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
mydestination = $myhostname, localhost.$mydomain, localhost
mydomain = mydoman.hk
myhostname = mail.mydomain.hk
mynetworks = 192.168.0.0/24, 127.0.0.0/8, 192.168.0.100/32, hash:/etc/postfix/access
myorigin = $myhostname
newaliases_path = /usr/bin/newaliases.postfix
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-2.2.8/README_FILES
relay_domains = mydomain.hk
relayhost = [smtp.i-cable.com]
sample_directory = /usr/share/doc/postfix-2.2.8/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
unknown_local_recipient_reject_code = 550

Million Thanks!

[new_linux_fans_jack]

Yes, I just recognized that I could just copy the aliase file from /etc to /etc/postfix and the postfix has started properly.

But I have got another problem with the user a/c and mailbox. I tried to create some Unix accounts but seems they didn't automatically create the mailboxes accordingly. (there is no such mailbox file under /var/mail, is it the right place btw?)

I could successfully authenticate the newly created Unix account thru the pop3 port on my Outlook, but I could not receive mail from there.

please advise!