System: Redhat AS3 postfix 2.2.5 cyrus-sasl 2.1.15 pam-mysql 0.6 dovecot 0.99.14 ( compile from source tarball)

The same email account and machine, using thunderbird 1.06 to get email thru dovecot pop3, it returned "Mail Server does not support secure authentication" But in outlook express , there is no such problem

I have tested SASL thru pam-mysql is work properly before install dovecot Below is my dovecot.conf

/etc/dovecot.conf base_dir = /var/run/dovecot/

protocols = imap pop3 imap_listen = * pop3_listen = *

ssl_disable = yes

login = imap login = pop3

login_dir = /var/run/dovecot-login

login_executable = /usr/local/libexec/dovecot/imap-login login_executable = /usr/local/libexec/dovecot/pop3-login

imap_executable = /usr/local/libexec/dovecot/imap pop3_executable = /usr/local/libexec/dovecot/pop3

disable_plaintext_auth = no login_user = dovecot

first_valid_uid = 1000 last_valid_uid = 1000

valid_chroot_dirs = /var/spool/virtual

default_mail_env = /var/spool/virtual/%u

auth = default auth_mechanisms = plain auth_userdb = mysql /etc/dovecot/mysql.conf auth_passdb = mysql /etc/dovecot/mysql.conf auth_executable = /usr/local/libexec/dovecot/dovecot-auth auth_user = dovecot-auth

/etc/dovecot/mysql.conf db_host = localhost db_port = 3306 db_unix_socket = /tmp/mysql.sock db = postfix db_user = postfixuser db_passwd = userpostfix db_client_flags = 0

password_query = SELECT password FROM mailbox WHERE username = '%u' user_query = SELECT maildir, 1000 AS uid, 1000 AS gid FROM mailbox WHERE username = '%u'