[Dovecot] "unknown user" with: Dovecot Pop3 - SASL pam Postfix - Authtentification

[noracentral at gmx.net]

Hallo

I build my Installation after HowTo with Archlinux packages:
        http://wiki.dovecot.org/HowTo/SimpleVirtualInstall

I can send e-mail, but pop3 failed: "unknown user"

For good popularity needed one or more 100% complete howto step-by-step 
reusable for full folk. (not many-many with small pieces solutions by 
problems...)

thanks
nora


Auth.log:
Sep 17 14:35:49 dns su: pam_unix(su:session): session opened for user 
vmail by (uid=0)
Sep 17 15:24:06 dns su: pam_unix(su:session): session closed for user vmail

Dovecot.log:
dovecot: Sep 19 08:32:40 Info: auth(default): client in: AUTH   1       
PLAIN   service=POP3    lip=212.254.241.22      rip=77.56.100.9 resp=
dovecot: Sep 19 08:32:40 Info: auth(default): client out: CONT  1
dovecot: Sep 19 08:32:40 Info: auth(default): client in: CONT   1       
AG1vZGVybmxvdmVAdmVyYmVuLmNoADEyMzQ1Njc4OTA=
dovecot: Sep 19 08:32:40 Info: auth(default): 
cache(modernlove at verben.ch,77.56.100.9): hit
dovecot: Sep 19 08:32:40 Info: auth(default): client out: OK    1       
user=modernlove at verben.ch
dovecot: Sep 19 08:32:40 Info: auth(default): master in: REQUEST        
709     24114   1
dovecot: Sep 19 08:32:40 Info: auth(default): 
passwd(modernlove at verben.ch,77.56.100.9): lookup
!!! unknown user dovecot: Sep 19 08:32:40 Info: auth(default): 
passwd(modernlove at verben.ch,77.56.100.9): unknown user
dovecot: Sep 19 08:32:40 Info: auth(default): master out: USER  709     
modernlove at verben.ch    uid=1000        gid=101 
home=/home/vmail/modernlove at verben.ch
dovecot: Sep 19 08:32:40 Info: pop3-login: Login: 
user=<modernlove at verben.ch>, method=PLAIN, rip=77.56.100.9, 
lip=212.254.241.22
dovecot: Sep 19 08:32:40 Info: POP3(modernlove at verben.ch): Disconnected: 
Logged out top=0/0, retr=0/0, del=0/0, size=0