[Dovecot] 2.1b6 imapc sync error

[Metro Domain Admin]

I received this error at the end of a migration from imapc to mdbox. Is
it because I wanted doveadm 'sync' instead of 'backup'? I didn't get
time to do any testing, but since you're pushing for the release, here
it is:

kerio2:~ adminuser$ /opt/dovecot/bin/doveadm  -o imapc_user=jsample  -o
imapc_password=******  -o imapc_host=*.*.*.*  sync -R  -u
jsample_dc at mydomain.com  imapc:/tmp/imapc
dsync(jsample_dc at mydomain.com): Error: Can't update mailbox
Archives/2011: Not supported
dsync(jsample_dc at mydomain.com): Error: Can't update mailbox
Archives/2012: Not supported
dsync(jsample_dc at mydomain.com): Error: Can't update mailbox INBOX: Not
supported

...etc, for all mailboxes in the account.


This is my userdb entry:

jsample_dc at mydomain.com:{***}password:502:6:IMAPC RECIPIENT::/bin/false:


kerio2:~ adminuser$ /opt/dovecot/bin/doveconf -n
# 2.1.rc6: /opt/dovecot-2.1.rc6/etc/dovecot/dovecot.conf
# OS: Darwin 9.8.0 Power Macintosh
auth_cache_negative_ttl = 0
auth_cache_size = 1 M
auth_debug = yes
auth_mechanisms = plain login
auth_username_format = %n at mydomain.com
auth_verbose = yes
disable_plaintext_auth = no
instance_name = dovecot-2.1.rc6
listen = 192.168.20.40
mail_home = /var/mail/%d/%n
mail_location = mdbox:~/mdbox
mail_plugin_dir = /opt/dovecot/lib/dovecot
mail_plugins = fts fts_squat    # I know, this is deprecated in 2.1
mail_privileged_group = mail
maildir_very_dirty_syncs = yes
namespace inbox {
  inbox = yes
  location =
  mailbox Drafts {
    special_use = \Drafts
  }
  mailbox Junk {
    special_use = \Junk
  }
  mailbox Sent {
    special_use = \Sent
  }
  mailbox "Sent Messages" {
    special_use = \Sent
  }
  mailbox Trash {
    special_use = \Trash
  }
  prefix = 
}
passdb {
  args = scheme=CRYPT username_format=%u /opt/dovecot/etc/dovecot/users
  driver = passwd-file
}
plugin {
  fts = squat
}
postmaster_address = postmaster at mydomain.com
protocols = imap lmtp
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = _postfix
    mode = 0660
    user = _postfix
  }
  unix_listener auth-userdb {
    group = mail
    mode = 0660
    user = adminuser
  }
}
service imap {
  executable = imap postlogin
}
service lmtp {
  unix_listener /var/spool/postfix/private/dovecot-lmtp {
    group = _postfix
    mode = 0666
    user = _postfix
  }
}
service postlogin {
  executable = script-login rawlog -t
}
service stats {
  fifo_listener stats-mail {
    mode = 00
  }
}
ssl_ca = </opt/local/apache2/conf/ssl/gd_bundle.crt
ssl_cert = </opt/local/apache2/conf/ssl/server4.crt
ssl_key = </opt/local/apache2/conf/ssl/server4.key
userdb {
  args = username_format=%u /opt/dovecot/etc/dovecot/users
  driver = passwd-file
}
verbose_proctitle = yes
protocol imap {
  mail_max_userip_connections = 16
}
kerio2:~ adminuser$