Problems with mailman configuration based on postfix(dropmail)

Question

Recently, I've build up an email system using postfix/mysql/dropmail and etc. All the modules were running smoothly. However, when I was to install mailman for mail list configuration, the problem came out.

I've built a mail list of several email address (let it be maillist@mydomain.com), but when I wanna send a mail there, it came out with:

Apr 16 20:06:26 mail postfix/smtpd[1107]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 550 5.1.1 <maillist@mydomain.com>: Recipient address rejected: User unknown; from=<wangjingfei@mydomain.com> to=<maillist@mydomain.com> proto=ESMTP helo=<localhost.localdomain>

I failed to figure it out the whole day. The following are configurations related to mailman:

Postfix: /etc/postfix/mail.cf

alias_database = hash:/etc/postfix/aliases
alias_maps = hash:/etc/aliases, hash:/etc/postfix/aliases, hash:/etc/mailman/aliases

# Configuration for mailman
#virtual_alias_domain = mydomain.com
luser_relay =
recipient_delimiter = +
owner_request_special = no
virtual_maps = mysql:/etc/postfix/mysql_virtual_alias_maps.cf, hash:/etc/mailman/virtual-mailman
virtual_alias_maps = $virtual_maps
transport_maps = hash:/etc/postfix/transport
relay_domains = mail.mydomain.com
mailman_destination_recipient_limit = 1

Postfix: /etc/postfix/master.cf

mailman   unix  -       n       n       -       -       pipe
  flags=FR user=mailman:mailman argv=/usr/lib/mailman/bin/postfix-to-mailman.py
  ${nexthop} ${user}

Mailman: /etc/mailman/aliases

## maillist mailing list
maillist:              "|/var/www/mailman/mail/mailman post maillist"
maillist-admin:        "|/var/www/mailman/mail/mailman admin maillist"
maillist-bounces:      "|/var/www/mailman/mail/mailman bounces maillist"
maillist-confirm:      "|/var/www/mailman/mail/mailman confirm maillist"
maillist-join:         "|/var/www/mailman/mail/mailman join maillist"
maillist-leave:        "|/var/www/mailman/mail/mailman leave maillist"
maillist-owner:        "|/var/www/mailman/mail/mailman owner maillist"
maillist-request:      "|/var/www/mailman/mail/mailman request maillist"
maillist-subscribe:    "|/var/www/mailman/mail/mailman subscribe maillist"
maillist-unsubscribe:  "|/var/www/mailman/mail/mailman unsubscribe maillist"

Mailman: /var/www/mailman/Mailman/mm_cfg.py

from socket import *
try:
    fqdn = getfqdn()
except:
    fqdn = 'mm_cfg_has_unknown_host_domains'

DEFAULT_URL_HOST   = 'mail.software.ict.ac.cn'
DEFAULT_EMAIL_HOST = 'software.ict.ac.cn'
MAT = 'Postfix'

POSTFIX_STYLE_VIRTUAL_DOMAINS= ['software.ict.ac.cn', 'software.ict.ac.cn']

# Because we've overriden the virtual hosts above add_virtualhost
# MUST be called after they have been defined.

add_virtualhost(DEFAULT_URL_HOST, DEFAULT_EMAIL_HOST)

I would be appreciate if anyone can help. Thank you!