[Dovecot] On IMAP vhost login, only Username being used

[hobie at rumormillnews.com]

Attempting IMAP SSL login on new installation, using Icedove (Debain
Thunderbird variant), login fails.  Logs show Dovecot attempting to match
username only, not username with domain name, on Vpopmail user, so of
course no match. Tried with '@' in full username, also with '%'. What's
missing?

Log shows:

Aug 24 19:30:48 debian dovecot: auth: Debug: client in: CONT<hidden>
Aug 24 19:30:48 debian dovecot: auth: Debug: Loading modules from
directory: /usr/local/lib/dovecot/auth
Aug 24 19:30:48 debian dovecot: auth: Debug: vpopmail(postmaster,[IP
redacted]): lookup user=postmaster domain=

Current config:

# 2.0.13: /usr/local/etc/dovecot/dovecot.conf
# OS: Linux 2.6.32-5-amd64 x86_64 Debian 6.0.2 ext3
auth_debug = yes
auth_verbose = yes
disable_plaintext_auth = no
first_valid_gid = 89
first_valid_uid = 89
mail_debug = yes
mail_location = maildir:/home/vpopmail/domains/%d/%n/Maildir
maildir_very_dirty_syncs = yes
passdb {
  driver = vpopmail
}
protocols = imap pop3
ssl_cert = </etc/ssl/certs/dovecot.pem
ssl_key = </etc/ssl/private/dovecot.pem
userdb {
  args = quota_template=quota_rule=*:backend=%q
  driver = vpopmail
}

--hobie