[exim] Problem with checking condition in acl section

Hi,

i use exim 4.5 with spamassassin for spam checks. I want to controll the use of
spamassassin in the acl_smtp_data section. Only if a domain is marked in the
database to check for spam, the spamassassin should check the mail otherwise
the mail is unchecked.

I define

    MYSQL_SPAM_IS_CHECKED = SELECT domain FROM MYSQL_DOMAINTABLE WHERE domain
='${quote_mysql:$domain}' AND spamcheck = 'y';

and in the acl_smtp_data section i made

    warn    message       = X-SA-Server: ${primary_hostname}\nX-SA-Score:
$spam_score\nX-SA-Spambar: $spam_bar
                spam          = nobody:true
        condition     = ${if eq{${lookup
mysql{MYSQL_SPAM_IS_CHECKED}{value}}}{$domain}}}

but it does work. With this condition the spamassassin don´t scan any email.

If i deactived the condition the spamassassin works fine. So i think that my
problem is the condition.

Thx for help.

Kai