[Exim] domain list question

In the documentation, it specifies that

domainlist foo = pgsql;select domain from domains where domain='$domain';

doesn't actually return the domain, but just returns either success or failure. Will

domainlist foo = ${lookup pgsql{select domain from domains}{$value}fail}

create an actual list of domains as if I'd specified them out manually, or do I have to replace newlines with : after the lookup to simulate having just written it out?

Kelley Reynolds