Ni hao!

I'd experienced a problem with pretty new installation of IRedMail.
Everything works allright except mail transfer to distant servers. When I'm trying to send email to any address outside my domain I get 550 error. What I doing wrong?

My configuration:
Latest LDAP distribution, Ubuntu server 10.04.3 LTS

Error log:

---
Feb 15 19:12:28 huginn postfix/smtpd[13071]: fatal: parameter "smtpd_recipient_r
estrictions": specify at least one working instance of: check_relay_domains, rej
ect_unauth_destination, reject, defer or defer_if_permit
Feb 15 19:14:29 huginn roundcube: SMTP Error: SMTP error: Failed to add recipien
t 'lg77@bk.ru' in /usr/share/apache2/roundcubemail-0.7/program/include/main.inc
on line 1745 (POST /mail/?_unlock=loading1329319894050&_lang=undefined?_task=mai
l&_action=send)
Feb 15 23:31:27 huginn roundcube: SMTP Error: SMTP error: Failed to add recipien
t 'lg77@bk.ru' in /usr/share/apache2/roundcubemail-0.7/program/include/main.inc
on line 1745 (POST /mail/?_unlock=loading1329335902400&_lang=undefined?_task=mai
l&_action=send)

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==== Provide required information to help troubleshoot and get quick answer ====
- Linux/BSD distribution name and version:
- iRedMail version and backend (LDAP/MySQL):
- Any related log? Log is helpful for troubleshooting.
====

Thanks in advance,
Max