[Exim] exim+postgresql+dbmail

Hello everybody.

I am trying to make exim work with dbmail. Dbmail stores mail, user
information, aliases etc in tables in postgres and I want to make exim
fetch data from those tables for authentication information. Due to the
nature of the tables I need to create views and stored procedures and such
to make sure the data is in the format that exim expects.

I have scoured the mailing list and the documentation on the web but I
still can't get it to go. To start with I wanted to simply get the local
domains to be read from a table so I did this.

hide pgsql_servers = localhost/dbmail/dbmail/dbmail
domainlist local_domains = ${lookup pgsql{select domain from
local_domains}{$value}fail}

This is just plain old cut and paste from my digging around on the web so I
don't really understand the syntax of the second line but it does not work.
It gives me the "lowest numbered MX record points to local host" error
which I understand is because the lookup is failing. There is no entry in
the paniclog. If I hard code the local hosts then it's OK.

Is there a decent explanation of database lookups anywhere? The
documentation is sparse to say the least. What am I doing wrong here?