Postfix 2.6.6 when you specify "Send copies of letters to e-mail" mail does not come. Where to look ?

Question

postfix

And so .. We have CentOS release 6.5 (Final)
postfix 2.6.6 without mysql support
through the control panel I create a mailbox - I send a letter - it comes without problems,
then I go to the control panel, I call editing the mailbox and I specify in the field "Send copies of letters to e- mail" I specify the email where to send a copy
in the /etc/aliases file, the entry I need appears,
for example ,
webmaster+beta.ru: [email protected]
when sending mail to [email protected], I receive a letter to this box, but also comes to the sender

"This is the mail system at host beta.ru.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
(expanded from ) : user
unknown -Postfix-Sender: rfc822; [email protected] Arrival-Date: Mon, 16 Jun 2014 18:10:32 +0600 (KGT) Final-Recipient: rfc822; [email protected] Original-Recipient: rfc822;[email protected] beta.ru Action: failed
Status: 5.1.1
Diagnostic-Code: x-unix; user unknown"

main.cf settings

alias_database = hash: / etc / aliases
file smtpd_client_restrictions = check_client_access hash: / etc / mail / access, permit_sasl_authenticated
smtpd_sender_restrictions = check_sender_access hash: / etc / mail / access, permit_sasl_authenticated
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, check_client_access hash: / etc / mail / access,check_sender_access hash:/etc/mail/access,check_recipient_access hash:/etc/mail/access,reject_unlisted_recipient, check_policy_service unix:/var/spool/postfix/postgrey/socket

Maybe someone has already solved this issue and will direct you in the right direction
Thanks!