[Dovecot] LMTP Proxy

Cassidy Larson
Wed, 03 Jul 2013 00:20:12 -0000

Trying to figure out Proxying with LMTP to a few back end storage servers
for quota checking before accepting email delivery on the front end nodes.

If I connect to the back end server directly via telnet, everything works
great.

If I use a front-end server to proxy to the back end server, I don't get
the same result.

Running 2.2.4 on both front and back end servers.

Any help would be appreciated.

------
backend dovecot.log:
dovecot: lmtp(72274): Error: userdb lookup(user at host*masteruser):
Disconnected unexpectedly
dovecot: auth: Fatal: master: service(auth): child 72272 killed with signal
11 (core not dumped)

------
front end dovecot.log:
dovecot: lmtp(7495): Debug: auth input:
user=user at host.comnopassword=<hidden> host=<backend_server_ip>
destuseruser at host.com*masteruser nologin=Y nodelay=Y proxy=Y
pass=<hidden> port=2525

------
front end dovecot.conf:
lmtp_proxy = yes
protocols = lmtp

protocol lmtp {
   postmaster_address = postmaster at mydomain.com
   mail_plugins = quota

  passdb {
    args = /usr/local/etc/dovecot/dovecot-sql.conf
    driver = sql
  }
}

service lmtp {
  client_limit = 5
  executable = lmtp
  idle_kill = 0
  process_limit = 0
  process_min_avail = 0
  protocol = lmtp
  service_count = 0
  inet_listener lmtp {
    address = <frontend_server_ip>
    port = 2525
  }
}
------
backend dovecot.conf:
auth_master_user_separator = *
lmtp_rcpt_check_quota = yes
passdb {
  args = /usr/local/etc/dovecot/dovecot-sql.conf
  driver = sql
  master = yes
}
userdb {
  args = /usr/local/etc/dovecot/dovecot-sql.conf
  driver = sql
}
service lmtp {
  client_limit = 5
  executable = lmtp -L
  idle_kill = 0
  process_limit = 0
  process_min_avail = 0
  protocol = lmtp
  service_count = 0
  inet_listener lmtp {
    address = <backend_server_ip>
    port = 2525
  }
}

protocol lmtp {
   info_log_path = /var/log/dovecot-lmtp.log
   postmaster_address = postmaster at infowest.com
   mail_plugins = quota
}