Postfix – User unknown in virtual mailbox table + authentification failed

I'm trying to set postfix with MySQL authentication. I can send mails (from postfixadmin) to different domains. The problem is that I cannot send any mail to my domain or even log-in to squirrelMail even if I've created new user in postfixadmin.

When I send an email to my domain it logs an error:

Jan 31 10:47:17 server postfix/proxymap[4534]: warning: table "mysql:/etc/postfix/mysql_relay_domains_maps.cf": empty lookup result for: "domain.tld" -- ignored
Jan 31 10:47:17 server postfix/smtpd[4533]: NOQUEUE: reject: RCPT from nat-simple12.ntkcz.de[195.113.241.228]: 550 5.1.1 <test@domain.tld>: Recipient address rejected: User unknown in virtual mailbox table; from=<test@workround.org> to=<test@domain.tld> proto=ESMTP helo=<workaround.org>

If I try to login to squirrelMail it logs:

Jan 31 11:15:42 server imapd: LOGIN FAILED, user=test@domain.tld, ip=[::ffff:127.0.0.1]
Jan 31 11:15:47 server imapd: LOGOUT, ip=[::ffff:127.0.0.1], rcvd=54, sent=332

my /etc/postfix/main.cf contains:

...
# my configuration
virtual_alias_maps = mysql:/etc/postfix/mysql_virtual_alias_maps.cf
virtual_mailbox_base = /home/virtual
virtual_mailbox_domains = mysql:/etc/postfix/mysql_virtual_domains_maps.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
virtual_transport = virtual
virtual_create_maildirsize = yes
virtual_mailbox_extended = yes
virtual_mailbox_limit_maps = mysql:/etc/postfix/mysql_virtual_mailbox_limit_maps.cf
virtual_mailbox_limit_override = yes
virtual_overquota_bounce = yes
relay_domains = proxy:mysql:/etc/postfix/mysql_relay_domains_maps.cf
...

I can't find any problem in my configuration. Does anybody see any problem or any direction I can move forward because I'm completely stuck.

Thanks,
Mateo