unknown smtpd restriction

[Gigadoc2]

I just set up my mailserver mostly following this guide: http://wiki.nefarius.at/linux/the_ueber_mail-server
Just set up some mailboxes, and Role Accounts.

Now, if someone tries to send me a mail, it gets rejected, and this is written into the logfiles: postfix/smtpd[9530]: warning: unknown smtpd restriction: "gigadoc2@"

This seems to be related to the Role Account entries (i redirect the role accounts to gigadoc2@mydomain.tld), and I traced it back to the following line in /etc/postfix/main.cf: check_recipient_access proxy:mysql:/etc/postfix/maps/access_recipient_roles.cf,

Now, mails seem to work when commenting this line, but i don't think this is a permament solution; what should this line actually be doing?