configuring virtual users

[max]

hello,

i would like to configure roundcubemail to accept email-names instead of usernames.

i have already read the howto_config.
the solution for a 'virtuser_file' works quite good.

but the other solution for a sql-query 'virtuser_query' seems not to work at all.
i already searched for a hint in the whole forum without success.

has anybody solved this?

regards