[Dovecot] Proxy Problems

[Richard Cooper]

Hi,

I'm trying to use dovecot as a proxy as described on http://wiki.dovecot.org/PasswordDatabase/ExtraFields/Proxy 
  but without much success. The problem is that when I send a IMAP  
login command dovecot is responding with "BYE Internal login failure.  
Refer to server log for more information." Can anyone help me shed  
light on this problem?

Here's the log (Username, password and IPs have been anonymised):

dovecot: Mar 27 13:07:11 Info: Dovecot v1.0.rc15 starting up
dovecot: Mar 27 13:07:12 Info: auth(default): passwd-file /root/ 
dovecot-proxy-test.passwd: Read 1 users
dovecot: Mar 27 13:07:29 Info: auth(default): client in: AUTH	1	PLAIN	 
service=IMAP	lip=192.168.0.1	rip=192.168.0.2	 
resp=WWVzIEkgYW5vbnltaXNlZCB0aGlzIHRvbyA7LSk=
dovecot: Mar 27 13:07:29 Info: auth(default): client out: OK	1	 
user=test_proxy	proxy	host=192.168.0.3	port=143	pass=password
dovecot: Mar 27 13:07:29 Info: auth(default): master in: REQUEST	1	 
11786	1
dovecot: Mar 27 13:07:29 Error: auth(default): Master request 11786.1  
not found
dovecot: Mar 27 13:07:29 Info: auth(default): master out: NOTFOUND	1
dovecot: Mar 27 13:07:29 Info: imap-login: Internal login failure:  
user=<test_proxy>, method=PLAIN, rip=192.168.0.2, lip=192.168.0.1

And here's my config according to dovecot -n

# /root/dovecot-proxy-test.conf
base_dir: /var/run/dovecot-proxy-test
log_path: /dev/stderr
protocols: imap
listen: *:10143
login_dir: /var/run/dovecot-proxy-test/login
login_executable: /usr/libexec/dovecot/imap-login
auth default:
   verbose: yes
   debug: yes
   debug_passwords: yes
   passdb:
     driver: passwd-file
     args: /root/dovecot-proxy-test.passwd
   userdb:
     driver: static
     args: uid=0 gid=0

/root/dovecot-proxy-test.passwd contains a single line:

test_proxy:::::::proxy=y host=192.168.0.3 port=143


I am on Cent OS 5 using dovecot version 1.0.rc15 from their official  
yum repositories. If I connect my client directly to 192.168.0.3:143  
using the same username and password everything works correctly.

Thanks in advance.

- Richard