problem in setting up proxy

[Ted]

Hello,

We're having difficulty with our updated cluster of dovecot servers
accessing the email storage on the NFS mounts.  It seems index files get
corrupted when 2 backend mailservers access the same account, and from
documentation setting up a director proxy in front of the backup
servers.  I'm trying to just set up a straight proxy first, which the
documents say is the first step, and although I can see the connections
coming into the server when I try to login via the proxy, the connection
times out and there are no logs from dovecot anywhere saying what
happened to the connection.

The configs I have set up for this in dovecot are:

dovecot.conf

# Protocols we want to be serving.
protocols = imap pop3

#when re-enabling quota enforcement add quota in below:
mail_plugins = $mail_plugins mail_log notify

protocol imap {
  # Space separated list of plugins to load (default is global
mail_plugins).
#when re-enabling quota enforcement add imap_quota in below:
  mail_plugins = $mail_plugins
}


# A comma separated list of IPs or hosts where to listen in for
connections.
# "*" listens in all IPv4 interfaces, "::" listens in all IPv6 interfaces.
# If you want to specify non-default ports or anything more complex,
# edit conf.d/master.conf.
#listen = *, ::

# Base directory where to store runtime data.
#base_dir = /var/run/dovecot/

# Name of this instance. In multi-instance setup doveadm and other commands
# can use -i <instance_name> to select which instance is used (an
alternative
# to -c <config_path>). The instance name is also added to Dovecot processes
# in ps output.
#instance_name = dovecot

# Greeting message for clients.
login_greeting = Welcome to easyMail.

shutdown_clients = yes

# Most of the actual configuration gets included below. The filenames are
# first sorted by their ASCII value and parsed in that order. The
00-prefixes
# in filenames are intended to make it easier to understand the ordering.
!include conf.d/*.conf

# A config file can also tried to be included without giving an error if
# it's not found:
!include_try local.conf

service auth {
  unix_listener auth-master {
    mode = 0600
    user = vmail
  }
}

conf.d/10-auth.conf

##
## Authentication processes
##
# Username formatting before it's looked up from databases. You can use
# the standard variables here, eg. %Lu would lowercase the username, %n
would
# drop away the domain if it was given, or "%n-AT-%d" would change the
'@' into
# "-AT-". This translation is done after auth_username_translation changes.
auth_username_format = %Lu

# Space separated list of wanted authentication mechanisms:
#   plain login digest-md5 cram-md5 ntlm rpa apop anonymous gssapi otp skey
#   gss-spnego
# NOTE: See also disable_plaintext_auth setting.
auth_mechanisms = plain login
#
# Password database is used to verify user's password (and nothing more).
# You can have multiple passdbs and userdbs. This is useful if you want to
# allow both system users (/etc/passwd) and virtual users to login without
# duplicating the system users into virtual database.
#
# <doc/wiki/PasswordDatabase.txt>
#
# User database specifies where mails are located and what user/group IDs
# own them. For single-UID configuration use "static" userdb.
#
# <doc/wiki/UserDatabase.txt>

#!include auth-deny.conf.ext
#!include auth-master.conf.ext

#!include auth-system.conf.ext
#!include auth-sql.conf.ext
#!include auth-ldap.conf.ext
#!include auth-passwdfile.conf.ext
#!include auth-checkpassword.conf.ext
#!include auth-vpopmail.conf.ext
!include auth-static.conf.ext

conf.d/auth-static.conf.ext

# Static passdb. Included from auth.conf.

# This can be used for situations where Dovecot doesn't need to verify the
# username or the password, or if there is a single password for all users:
#
#  - proxy frontend, where the backend verifies the password
#  - proxy backend, where the frontend already verified the password
#  - authentication with SSL certificates
#  - simple testing

  passdb static {
   driver = static
   args = nopassword=y
   default_fields = proxy=y host=10.5.10.121
  }


#passdb {
#  driver = static
#  args = password=test
#}

#userdb {
#  driver = static
#  args = uid=vmail gid=vmail home=/home/%u
#}

conf.d/10-logging.conf

##
## Log destination.
##

# Log file to use for error messages. "syslog" logs to syslog,
# /dev/stderr logs to stderr.
#log_path = syslog

# Log file to use for informational messages. Defaults to log_path.
#info_log_path =
# Log file to use for debug messages. Defaults to info_log_path.
#debug_log_path =

# Syslog facility to use if you're logging to syslog. Usually if you don't
# want to use "mail", you'll use local0..local7. Also other standard
# facilities are supported.
#syslog_facility = mail

##
## Logging verbosity and debugging.
##

# Log unsuccessful authentication attempts and the reasons why they failed.
auth_verbose = yes

# In case of password mismatches, log the attempted password. Valid
values are
# no, plain and sha1. sha1 can be useful for detecting brute force password
# attempts vs. user simply trying the same password over and over again.
# You can also truncate the value to n chars by appending ":n" (e.g.
sha1:6).
#auth_verbose_passwords = no

# Even more verbose logging for debugging purposes. Shows for example SQL
# queries.
auth_debug = yes

# In case of password mismatches, log the passwords and used scheme so the
# problem can be debugged. Enabling this also enables auth_debug.
#auth_debug_passwords = no

# Enable mail process debugging. This can help you figure out why Dovecot
# isn't finding your mails.
mail_debug = yes

# Show protocol level SSL errors.
verbose_ssl = yes

# mail_log plugin provides more event logging for mail processes.
plugin {
  # Events to log. Also available: flag_change append
  #mail_log_events = delete undelete expunge copy mailbox_delete
mailbox_rename
  # Available fields: uid, box, msgid, from, subject, size, vsize, flags
  # size and vsize are available only for expunge and copy events.
  #mail_log_fields = uid box msgid size
}


I'm basically expecting this to forward the login requests on to
10.5.10.121 when I try to access the email account through the proxy. 
When I attempt this I am able to see the connections in a tcp dump, but
dovecot does not log anything about the attempt.  I clearly must be
missing something, can you let me know what I need to do or check? 

Thank you
Ted
easyDNS Technologies