[Dovecot] dovecot: pop3-login: Disconnected (tried to use disabled plaintext auth): method=PLAIN

[John Espiro]

First, my problem.  Settings are below that...

Everything works fine - I can login to webmail (users are tied to
LDAP).  I can send and receive email via my Thunderbird Client.

However in my mail.err log I see lots of messages that say:

dovecot: pop3-login: Disconnected (tried to use disabled plaintext
auth): method=PLAIN

1.) What does that mean, and how can I solve it?
2.) With regards to pop3s I am not altogether sure that I am using the
right config in my dovecot.conf file (also below).  Can someone let me know?


Version:
==================
dovecot --version = 1.2.12

System:
==================
Ubuntu Server 10.10 (64bit)

dovecot -n
==================
# 1.2.12: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.35.4-rscloud x86_64 Ubuntu 10.10
log_timestamp: %Y-%m-%d %H:%M:%S
protocols: pop3 pop3s imap imaps
login_dir: /var/run/dovecot/login
login_executable(default): /usr/lib/dovecot/imap-login
login_executable(imap): /usr/lib/dovecot/imap-login
login_executable(pop3): /usr/lib/dovecot/pop3-login
mail_privileged_group: mail
mail_location: mbox:~/mail:INBOX=/var/mail/%u
mbox_write_locks: fcntl dotlock
mail_executable(default): /usr/lib/dovecot/imap
mail_executable(imap): /usr/lib/dovecot/imap
mail_executable(pop3): /usr/lib/dovecot/pop3
mail_plugin_dir(default): /usr/lib/dovecot/modules/imap
mail_plugin_dir(imap): /usr/lib/dovecot/modules/imap
mail_plugin_dir(pop3): /usr/lib/dovecot/modules/pop3
auth default:
  passdb:
    driver: pam
  userdb:
    driver: passwd

Dovecot.conf
==================
egrep -v "^[[:space:]]*#|^$" /etc/dovecot/dovecot.conf
protocols = pop3 pop3s imap imaps
log_timestamp = "%Y-%m-%d %H:%M:%S "
ssl = yes
ssl_cert_file = /etc/ssl/certs/dovecot.pem
ssl_key_file = /etc/ssl/private/dovecot.pem
login_dir = /var/run/dovecot/login
   mail_location = mbox:~/mail:INBOX=/var/mail/%u
mail_privileged_group = mail
protocol imap {
  login_executable = /usr/lib/dovecot/imap-login
  mail_executable = /usr/lib/dovecot/imap
}

protocol pop3 {
  login_executable = /usr/lib/dovecot/pop3-login
  mail_executable = /usr/lib/dovecot/pop3
  pop3_uidl_format = %08Xu%08Xv
}
protocol managesieve {
}
auth default {
  mechanisms = plain
  passdb pam {
  }
  userdb passwd {
  }
  user = root
  !include_try /etc/dovecot/auth.d/*.auth
}
dict {
}
plugin {
}
!include_try /etc/dovecot/conf.d/*.conf