[Dovecot] Dovecot Migration: Retrieving/Logging POP/IMAP Passwords in Plaintext

[Traiano Welcome]

Hi List

I'm currently in the process of migrating my dovecot imap/pop users to a
new server and have to extract their passwords in order to import them into
the new system (different password encryption schemes).

I've tried enabling auth_* debug parameters in my dovecot.conf in the hope
that this would result in logging plaintext passwords to the dovecot log.
However dovecot does not log the passwords in plaintext under any debugging
configuration.

My question: Is there any other configuration of dovecot that would allow
me to capture POP/IMAP passwords at a successful login time?

Dovecot version:  1.0.7 (from dovecot-1.0.7-7.el5_7.1 rpm)

The output of dovecot -n is:

---
# 1.0.7: /etc/dovecot.conf
info_log_path: /var/log/dovecot.debug
verbose_ssl: yes
login_dir: /var/run/dovecot/login
login_executable(default): /usr/libexec/dovecot/imap-login
login_executable(imap): /usr/libexec/dovecot/imap-login
login_executable(pop3): /usr/libexec/dovecot/pop3-login
mail_location: mbox:~:INBOX=~/Mailbox
mail_debug: yes
mail_executable(default): /usr/libexec/dovecot/imap
mail_executable(imap): /usr/libexec/dovecot/imap
mail_executable(pop3): /usr/libexec/dovecot/pop3
mail_plugin_dir(default): /usr/lib64/dovecot/imap
mail_plugin_dir(imap): /usr/lib64/dovecot/imap
mail_plugin_dir(pop3): /usr/lib64/dovecot/pop3
auth default:
  mechanisms: plain login
  verbose: yes
  debug: yes
  debug_passwords: yes
  passdb:
    driver: pam
  userdb:
    driver: passwd
  socket:
    type: listen
    client:
      path: /var/run/dovecot/auth-client
      mode: 438
---

My dovecot.conf is as follows:

------
info_log_path = /var/log/dovecot.debug
verbose_ssl = yes
mail_location = mbox:~:INBOX=~/Mailbox
mail_debug = yes
protocol imap {
}
protocol pop3 {
}
protocol lda {
  postmaster_address = postmaster at example.com
}
auth_verbose = yes
auth_debug = yes
auth_debug_passwords = yes
auth default {
  mechanisms = plain login
  passdb pam {
  }
  userdb passwd {
  }
  user = root
  socket listen {
    client {
      path = /var/run/dovecot/auth-client
      mode = 0666
    }
  }
}
dict {
}
plugin {
}
---

Many thanks in advance!
Traiano