[exim] failed to expand condition

Hello Guys,

I am new to exim. I want to block all remote and local outbound mails being
sent from one domain, but the mail should work if the recpt address is in
same domain. I just wrote a simple acl for this but it always shows the
following error.

ACL
=====
${ if and { { ${lookup{$sender_address_domain} lsearch
{/etc/blocked_domains}}} {!eqi {$sender_address_domain}
{${domain:$h_to:}}}} {true}{false}}

Error
=====
failed to expand condition "${if and{{bool_lax{${if and{{bool_lax{NULL}

Thanks,