[Dovecot] "Waiting for authentication process to respond" for invalid users with auth_dovecot

[Ibrahim Harrani]

Hi,

I am testing dovecot 2.0.13 and 2.0.14 with qmail-ldap and
auth_dovecot patch. If i login to dovecot (pop3/imap) with correct
user and password.
no problem, I can login immediately. but if I try with nonexistant
user, dovecot does not immediate answer, wait for a while and says
"Waiting for authentication process to respond."
auth_dovecot process remains working in the background.
How can I avoid this situation?

# telnet 0 143
Trying 0.0.0.0...
Connected to 0.
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE
IDLE STARTTLS AUTH=PLAIN] Dovecot ready.
o login validuser validpass
o OK [CAPABILITY IMAP4rev1 LITERAL+ SASL

o login validuser wrongpass
o NO [UNAVAILABLE] Temporary authentication failure.

o login non-existant anypass
* OK Waiting for authentication process to respond..


Here is output of dovecot -n

# OS: Linux 2.6.32-71.el6.x86_64 x86_64 CentOS Linux release 6.0 (Final)
auth_debug = yes
auth_verbose = yes
base_dir = /var/run/dovecot
disable_plaintext_auth = no
first_valid_gid = 100
last_valid_gid = 65000
last_valid_uid = 65000
listen = *
log_path = /var/log/dovecot
mail_debug = yes
mail_location = maildir:~/Maildir
passdb {
  args =/opt/qmail/smtp/bin/auth_dovecot ./Maildir/
  driver = checkpassword
}
plugin {

  mechanisms = plain login
  quota = maildir

}
protocols = imap pop3
service imap-login {
  inet_listener imaps {
    port = 993
    ssl = yes
  }
  process_min_avail = 1
}
service imap-postlogin {
  executable = script-login /opt/qmail/scripts/dovecotpostlogin.sh
}
service imap {
  executable = imap imap-postlogin
}
service pop3-login {
  inet_listener pop3s {
    port = 995
    ssl = yes
  }
  process_min_avail = 1
}
ssl_cert = </etc/ssl/certs/mail.pem
ssl_cipher_list = ALL
ssl_key = </etc/ssl/private/mail.pem
userdb {
  driver = prefetch
}
verbose_proctitle = yes
verbose_ssl = yes
protocol imap {
  mail_plugins = quota
  ssl_cert = </etc/ssl/certs/mail.pem
  ssl_key = </etc/ssl/private/mail.pem
}
protocol pop3 {
  mail_plugins = quota
  ssl_cert = </etc/ssl/certs/mail.pem
  ssl_key = </etc/ssl/private/mail.pem
}