[Dovecot] Virtual-Auth-Problem "user unknown"

[strace at letras.net]

Hi,

> Is the user in the file as "user" or "user at domain"? passwd.%d means it
> should be there as "user". If you want "user at domain", use passwd.%0.d
 
passwd.%0.d solved it. Maybe I had read the docs too fast.

Thanks a lot,
Werner