Master auth only

[azurit at pobox.sk]

Hi,

i'm trying to configure Dovecot proxy with user authentication on  
proxy side only, so backends will authenticate using master password  
(proxy is configured to send it). The problem is that Dovecot, on  
backends, is telling me that i need to configure at least one auth  
mechanism:

auth: Fatal: No passdbs specified in configuration file. LOGIN  
mechanism needs one


The master auth is correctly configured.

I want to accomplished to have user database only on one place  
(=proxy). Any hints?

azur