[Exim] SQL lookup fallthrough

Hi!

How do I write a mySQL-router that, if the lookup fails,
continues to the next router?

I put the router after the system_aliases router like this:


system_aliases:
driver = redirect
allow_fail
allow_defer
data = ${lookup{$local_part}lsearch{/etc/aliases}}
# user = exim
file_transport = address_file
pipe_transport = address_pipe

mysql_system_aliases:
driver = redirect
allow_fail
file_transport = address_file
pipe_transport = address_pipe
data = ${lookup mysql{select members.emailaddress from members,
$local_part where members.sheetnumber =
$local_part.sheetnumber}{$value}fail}


after this comes the standard userforward etc.

The lookup works fine, but if it fails, the script doesn't continue to the
next router.
What am I doing wrong?

Thank you for your time,

/Bo