Резервная копия doveadm не передает почту из корневого INBOX

Я пытаюсь перенести почту IMAP с dovecot 1.1.20apple0.5 (osx) на dovecot 2.2.33.2 (ubuntu). Я использую «doveadm backup» для переноса данных. Он отлично работает для всех вложенных папок, но корневой ящик INBOX остается пустым на новом сервере. Я подозреваю, что проблема связана с разделителем иерархии («.» На предыдущем сервере, «/» на новом) или с префиксом пространства имен (установленным на «INBOX /» на новом сервере). Любой намек?

показывает, что в INBOX нет сообщений:

# doveadm mailbox status -u (myuser) all INBOX
INBOX messages=0 recent=0 uidnext=1 uidvalidity=1553630060 unseen=0 highestmodseq=1 vsize=0 guid=d54cd42849739b5cb5790000ed87e144 firstsaved=18446744073709551615

показывает, что в подкаталоге есть сообщения:

# doveadm mailbox status -u (myuser) all INBOX/Sent
INBOX/Sent messages=253 recent=0 uidnext=8721 uidvalidity=1263328366 unseen=0 highestmodseq=256 vsize=16335358 guid=bfb2e03fdce327671e82bf173b1ccb8b firstsaved=1553634631

Команда, которую я запускаю на новом сервере для переноса данных:

# doveadm -o mail_fsync=never backup -R -u (myuser) imapc:

Моя конфигурация на новом сервере :

# doveadm -n
# 2.2.33.2 (d6601f4ec): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.4.21 (92477967)
# OS: Linux 4.15.0-46-generic x86_64 Ubuntu 18.04.2 LTS 
auth_default_realm = example.com
doveadm_password =  # hidden, use -P to show it
doveadm_port = 53683
first_valid_uid = 200
imapc_features = rfc822.size fetch-headers
imapc_host = oldmail.example.com
imapc_master_user = (removed)
imapc_password =  # hidden, use -P to show it
imapc_user = %n
last_valid_uid = 200
mail_location = mbox:~/mail:INBOX=/var/mail/%u
mail_plugins = " notify replication zlib quota"
mail_prefetch_count = 20
mail_privileged_group = mail
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date index ihave duplicate mime foreverypart extracttext
mdbox_rotate_size = 10 M
namespace inbox {
  inbox = yes
  location = 
  mailbox "Éléments envoyés" {
    special_use = \Sent
  }
  mailbox "Éléments supprimés" {
    special_use = \Trash
  }
  mailbox Brouillon {
    special_use = \Drafts
  }
  mailbox "Courrier indésirable" {
    special_use = \Junk
  }
  mailbox Drafts {
    auto = subscribe
    special_use = \Drafts
  }
  mailbox Junk {
    auto = subscribe
    special_use = \Junk
  }
  mailbox Sent {
    auto = subscribe
    special_use = \Sent
  }
  mailbox "Sent Messages" {
    special_use = \Sent
  }
  mailbox Trash {
    auto = subscribe
    special_use = \Trash
  }
  prefix = INBOX/
  separator = /
}
passdb {
  args = /etc/dovecot/dovecot-ldap.conf.ext
  driver = ldap
}
plugin {
  mail_replica = tcps:mail2.example.com:53683
  quota = count:User quota
  quota_grace = 10%%
  quota_rule = *:storage=10G
  quota_rule2 = INBOX/Trash:storage=+100M
  quota_vsizes = yes
  quota_warning = storage=100%% quota-warning 100 %u
  quota_warning2 = storage=95%% quota-warning 95 %u
  quota_warning3 = storage=90%% quota-warning 90 %u
  quota_warning4 = storage=85%% quota-warning 85 %u
  quota_warning5 = storage=75%% quota-warning 75 %u
  quota_warning6 = -storage=80%% quota-warning '-80' %u
  quota_warning7 = -storage=100%% quota-warning '-100' %u
  sieve = /var/vmail/domains/%Ld/%Ln/.dovecot.sieve
  sieve_before = /var/vmail/sieve/before.sieve
  sieve_default = /var/vmail/sieve/default.sieve
  sieve_global = /var/vmail/sieve/global
  zlib_save = lz4
}
protocols = " imap lmtp sieve"
service aggregator {
  fifo_listener replication-notify-fifo {
    user = vmail
  }
  unix_listener replication-notify {
    user = vmail
  }
}
service auth {
  inet_listener {
    address = (removed)
    port = 55123
  }
  unix_listener /var/spool/postfix/private/auth {
    mode = 0666
  }
}
service doveadm {
  inet_listener {
    port = 53683
    ssl = yes
  }
}
service imap-login {
  inet_listener imap {
    port = 0
  }
  process_min_avail = 10
}
service lmtp {
  unix_listener /var/spool/postfix/private/dovecot-lmtp {
    group = postfix
    mode = 0660
    user = postfix
  }
}
service quota-warning {
  executable = script /usr/local/bin/quota-warning.sh
  unix_listener quota-warning {
    user = vmail
  }
}
service replicator {
  process_min_avail = 1
  unix_listener replicator-doveadm {
    mode = 0600
    user = vmail
  }
}
ssl = required
ssl_cert = </etc/ssl/example/example.com.crtbundle
ssl_client_ca_dir = /etc/ssl/certs
ssl_key =  # hidden, use -P to show it
userdb {
  args = /etc/dovecot/dovecot-ldap.conf.ext
  driver = ldap
}
verbose_proctitle = yes
protocol lmtp {
  mail_plugins = " notify replication zlib quota sieve"
  postmaster_address = postmaster@example.com
}
protocol imap {
  mail_plugins = " notify replication zlib quota imap_zlib imap_quota"
}

Настроить LDAP

# cat /etc/dovecot/dovecot-ldap.conf.ext | grep -v "^#" | grep -v "^$"
uris = ldaps://dc1.ad.example.com ldaps://dc2.ad.example.com
dn = (removed)
dnpass = (removed)
auth_bind = yes
base = (removed)
scope = subtree
deref = never
user_filter = (&(mail=%u)(memberOf:1.2.840.113556.1.4.1941:=CN=acces_courriels,(removed))(&(|(objectclass=person))(!(UserAccountControl:1.2.840.113556.1.4.803:=2))))
pass_filter = (&(mail=%u)(memberOf:1.2.840.113556.1.4.1941:=CN=acces_courriels,(removed))(&(|(objectclass=person))(!(UserAccountControl:1.2.840.113556.1.4.803:=2))))
iterate_filter = (&(mail=*)(memberOf:1.2.840.113556.1.4.1941:=CN=acces_courriels,(removed))(&(|(objectclass=person))(!(UserAccountControl:1.2.840.113556.1.4.803:=2))))
iterate_attrs = mail=user
user_attrs = \
  =quota_rule=*:storage=%{ldap:division:10G}, \
  =home=/var/vmail/domains/%Ld/%Ln, \
  =mail=mdbox:/var/vmail/domains/%Ld/%Ln/mdbox, \
  =uid=200, \
  =gid=200