[Dovecot] dovecot pop3 proxy with AUTH PLAIN

[Luis Barrueco]

Hi,
 I tried as hard as I could, but I couldn't get this working. So here
I come begging for help :)

I need to configure dovecot to proxy some users' incoming pop3
connections to another server running the Zimbra Collaboration Suite,
trying to log into zimbra via a master password. The problem I found
is that zimbra only allows me to log in as a master user with the
"AUTH PLAIN" mechanism, but it seems that dovecot uses the "USER....
PASS" authentication when proxying.

Am I missing something? Has anyone ever tried to do the proxy+master
password to zimbra? I'll post my configurations down here. I really
appreciate your help-
----------------------------- dovecot version:
1.0.13

----------------------------- "dovecot -n" output:
# 1.0.13: /usr/local/etc/dovecot.conf
protocols: imap pop3
ssl_disable: yes
disable_plaintext_auth: no
login_dir: /usr/local/var/run/dovecot/login
login_executable(default): /usr/local/libexec/dovecot/imap-login
login_executable(imap): /usr/local/libexec/dovecot/imap-login
login_executable(pop3): /usr/local/libexec/dovecot/pop3-login
mail_privileged_group: mail
mail_executable(default): /usr/local/libexec/dovecot/imap
mail_executable(imap): /usr/local/libexec/dovecot/imap
mail_executable(pop3): /usr/local/libexec/dovecot/pop3
mail_plugin_dir(default): /usr/local/lib/dovecot/imap
mail_plugin_dir(imap): /usr/local/lib/dovecot/imap
mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3
pop3_uidl_format(default):
pop3_uidl_format(imap):
pop3_uidl_format(pop3): %08Xu%08Xv
auth default:
  passdb:
    driver: pam
  passdb:
    driver: sql
    args: /etc/dovecot/dovecot-sql.conf
  userdb:
    driver: passwd

----------------------------- /usr/local/etc/dovecot-sql.conf:
driver = mysql
connect = host=172.16.0.252 dbname=dovecot user=usuario_dovecot password=miclave
password_query = SELECT password, 'secret_zimbra' as pass, host,
destuser, 'Y' AS proxy FROM proxy WHERE user = '%u'

----------------------------- sudo tcpdump -w output_tcpdump -i eth0
dst host 172.16.0.20 and dst port 110:
.........USER mnunez master
.........
.........PASS secret_zimbra
-----------------------------


I hope this information was helpful!

Cheers.