[Dovecot] Dovecot not honoring configuration settings (auth failure)

[Jeffrey Walton]

My dovecot.conf has the following:

    # No results when searching the wiki
    disable_plaintext_auth = no

    # http://wiki2.dovecot.org/Authentication/Mechanisms
    auth_mechanisms = plain login digest-md5 cram-md5

When I attempt to run imapsync, I receive an error:

    Host2: <host> says it has NO CAPABILITY for AUTHENTICATE LOGIN

imapsync also dumps the helo string, and it is missing:

    Host2: * OK [CAPABILITY IMAP4rev1 LITERAL+ ... STARTTLS
AUTH=PLAIN] Dovecot ready.

I've restarted the dovecot service with 'service dovecot restart' and
even rebooted the machine.

There is nothing reported in any on the log files
(/var/mail/dovecot.log and /var/log/mail.<level>).

Any ideas why dovecot is not honoring the setting in its config file?

**********

# dovecot --version
2.1.7
# doveconf -n
# 2.1.7: /etc/dovecot/dovecot.conf
# OS: Linux 3.2.0-4-686-pae i686 Debian 7.4
disable_plaintext_auth = no
log_path = /var/log/dovecot.log
mail_location = mbox:~/mail:INBOX=/var/mail/%u
namespace inbox {
  inbox = yes
  location =
  mailbox Drafts {
    special_use = \Drafts
  }
  ...
  prefix =
}
passdb {
  args = /var/mail/%d/users
  driver = passwd-file
}
passdb {
  driver = pam
}
plugin {
  sieve = ~/.dovecot.sieve
  sieve_dir = ~/sieve
}
protocols = " imap pop3"
ssl_cert = </etc/dovecot/dovecot.pem
ssl_key = </etc/dovecot/private/dovecot.pem
userdb {
  driver = passwd
}