Dovecot IMAP サーバーと Horde Groupware ActiveSync - IMAP サーバーが変更された状態を報告しない

Question

私は、Debian Linux 上で Dovecot IMAP サーバーを搭載した Horde グループウェアを実行しています。

Horde の Web UI を使用するとうまく機能しますが、ActiveSync を使用すると問題が発生します。

Android で BlueMail などのクライアント アプリを使用すると、INBOX に最新の電子メール メッセージが表示されません。

ActiveSync ログには次のように表示されます。

[163168][2022-11-11T15:08:44+00:00] >>>: INBOX IMAP PREVIOUS MODSEQ: 190086

この行は、INBOX が最後に同期されたときの MODSEQ 値が 190086 であったことを示しています。IMAP サーバーによって報告される modseq 値は、メールボックスにメッセージが追加されるたびに増加する必要があります。

[163168][2022-11-11T15:08:44+00:00] >>>: IMAP status: a:4:{s:8:"messages";i:6874;s:7:"uidnext";i:157933;s:11:"uidvalidity";i:1291740963;s:13:"highestmodseq";i:190086;}

この行は、IMAPサーバーによって報告されたCURRENT MODSEQを示しています。サーバーが変更された状態を報告していないことを示しています。

どうしてそんなことが起こり得るのでしょうか? 受信トレイに新しいメールが届いているのに、アプリに表示されません。

Thunderbird 経由で IMAP サーバーに直接アクセスすると、すべての新しい電子メールが表示されます。

以前は FreeBSD 上の Dovecot サーバーで動作していましたが、Dovecot を Debian Linux に移行しました。

Dovecot の設定で何が問題なのか、何かアイデアはありますか?

私は主に Dovecot の標準設定、特に IMAP 設定を使用しています。

これが私の IMAP 固有の設定です:

##
## IMAP specific settings
##

# If nothing happens for this long while client is IDLEing, move the connection
# to imap-hibernate process and close the old imap process. This saves memory,
# because connections use very little memory in imap-hibernate process. The
# downside is that recreating the imap process back uses some resources.
#imap_hibernate_timeout = 0

# Maximum IMAP command line length. Some clients generate very long command
# lines with huge mailboxes, so you may need to raise this if you get
# "Too long argument" or "IMAP command line too large" errors often.
#imap_max_line_length = 64k

# IMAP logout format string:
#  %i - total number of bytes read from client
#  %o - total number of bytes sent to client
#  %{fetch_hdr_count} - Number of mails with mail header data sent to client
#  %{fetch_hdr_bytes} - Number of bytes with mail header data sent to client
#  %{fetch_body_count} - Number of mails with mail body data sent to client
#  %{fetch_body_bytes} - Number of bytes with mail body data sent to client
#  %{deleted} - Number of mails where client added \Deleted flag
#  %{expunged} - Number of mails that client expunged, which does not
#                include automatically expunged mails
#  %{autoexpunged} - Number of mails that were automatically expunged after
#                    client disconnected
#  %{trashed} - Number of mails that client copied/moved to the
#               special_use=\Trash mailbox.
#  %{appended} - Number of mails saved during the session
#imap_logout_format = in=%i out=%o deleted=%{deleted} expunged=%{expunged} \
#  trashed=%{trashed} hdr_count=%{fetch_hdr_count} \
#  hdr_bytes=%{fetch_hdr_bytes} body_count=%{fetch_body_count} \
#  body_bytes=%{fetch_body_bytes}

# Override the IMAP CAPABILITY response. If the value begins with '+',
# add the given capabilities on top of the defaults (e.g. +XFOO XBAR).
#imap_capability =

# How long to wait between "OK Still here" notifications when client is
# IDLEing.
#imap_idle_notify_interval = 2 mins

# ID field names and values to send to clients. Using * as the value makes
# Dovecot use the default value. The following fields have default values
# currently: name, version, os, os-version, support-url, support-email,
# revision.
#imap_id_send =

# ID fields sent by client to log. * means everything.
#imap_id_log =

# Workarounds for various client bugs:
#   delay-newmail:
#     Send EXISTS/RECENT new mail notifications only when replying to NOOP
#     and CHECK commands. Some clients ignore them otherwise, for example OSX
#     Mail (<v2.1). Outlook Express breaks more badly though, without this it
#     may show user "Message no longer in server" errors. Note that OE6 still
#     breaks even with this workaround if synchronization is set to
#     "Headers Only".
#   tb-extra-mailbox-sep:
#     Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
#     adds extra '/' suffixes to mailbox names. This option causes Dovecot to
#     ignore the extra '/' instead of treating it as invalid mailbox name.
#   tb-lsub-flags:
#     Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g. mbox).
#     This makes Thunderbird realize they aren't selectable and show them
#     greyed out, instead of only later giving "not selectable" popup error.
#
# The list is space-separated.
#imap_client_workarounds =

# Host allowed in URLAUTH URLs sent by client. "*" allows all.
#imap_urlauth_host =

# Enable IMAP LITERAL- extension (replaces LITERAL+)
#imap_literal_minus = no

# What happens when FETCH fails due to some internal error:
#   disconnect-immediately:
#     The FETCH is aborted immediately and the IMAP client is disconnected.
#   disconnect-after:
#     The FETCH runs for all the requested mails returning as much data as
#     possible. The client is finally disconnected without a tagged reply.
#   no-after:
#     Same as disconnect-after, but tagged NO reply is sent instead of
#     disconnecting the client. If the client attempts to FETCH the same failed
#     mail more than once, the client is disconnected. This is to avoid clients
#     from going into infinite loops trying to FETCH a broken mail.
#imap_fetch_failure = disconnect-immediately

protocol imap {
  # Space separated list of plugins to load (default is global mail_plugins).
  #mail_plugins = $mail_plugins

  # Maximum number of IMAP connections allowed for a user from each IP address.
  # NOTE: The username is compared case-sensitively.
  #mail_max_userip_connections = 10

my maildir 固有の設定:

##
## Maildir-specific settings
##

# By default LIST command returns all entries in maildir beginning with a dot.
# Enabling this option makes Dovecot return only entries which are directories.
# This is done by stat()ing each entry, so it causes more disk I/O.
# (For systems setting struct dirent->d_type, this check is free and it's
# done always regardless of this setting)
#maildir_stat_dirs = no

# When copying a message, do it with hard links whenever possible. This makes
# the performance much better, and it's unlikely to have any side effects.
#maildir_copy_with_hardlinks = yes

# Assume Dovecot is the only MUA accessing Maildir: Scan cur/ directory only
# when its mtime changes unexpectedly or when we can't find the mail otherwise.
maildir_very_dirty_syncs = no

# If enabled, Dovecot doesn't use the S=<size> in the Maildir filenames for
# getting the mail's physical size, except when recalculating Maildir++ quota.
# This can be useful in systems where a lot of the Maildir filenames have a
# broken size. The performance hit for enabling this is very small.
#maildir_broken_filename_sizes = no

# Always move mails from new/ directory to cur/, even when the \Recent flags
# aren't being reset.
#maildir_empty_new = no

MODSEQ が更新されない理由を知っている人はいますか?

ダブコット -n:

# 2.3.13 (89f716dc2): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.13 (cdd19fe3)
# OS: Linux 5.10.0-19-amd64 x86_64 Debian 11.5
# Hostname: mail01.public.forberger-online.de
auth_mechanisms = plain login
mail_location = maildir:~/.maildir
mail_privileged_group = mail
mailbox_list_index_include_inbox = 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 {
  driver = pam
}
protocols = " imap"
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
}
service imap-login {
  client_limit = 256
  inet_listener imap {
    address = 192.168.108.1, 127.0.0.1, [::1]
    port = 143
  }
  inet_listener imaps {
    address = 192.168.108.1, 127.0.0.1, [::1]
    port = 993
    ssl = yes
  }
  process_min_avail = 6
}
ssl_ca = </etc/letsencrypt/live/mail.forberger-online.de/chain.pem
ssl_cert = </etc/letsencrypt/live/mail.forberger-online.de/cert.pem
ssl_client_ca_dir = /etc/ssl/certs
ssl_dh = # hidden, use -P to show it
ssl_key = # hidden, use -P to show it
ssl_min_protocol = TLSv1.2
userdb {
  driver = passwd
}

重要: フォルダー INBOX の MODSEQ は増加しません:

* OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE LITERAL+ AUTH=PLAIN AUTH=LOGIN] Dovecot (Debian) ready.
A login REDACTED REDACTED
A OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS THREAD=ORDEREDSUBJECT MULTIAPPEND URL-PARTIAL CATENATE UNSELECT CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS BINARY MOVE SNIPPET=FUZZY PREVIEW=FUZZY STATUS=SIZE SAVEDATE LITERAL+ NOTIFY SPECIAL-USE] Logged in
A status INBOX (messages)
* STATUS INBOX (MESSAGES 7247)
A OK Status completed (0.001 + 0.000 secs).
1 SELECT Inbox
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft $MDNSent Junk NonJunk $label4 $label1 $label2 $label3 $label5 Old $Forwarded NOTJUNK $has_cal)
* OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft $MDNSent Junk NonJunk $label4 $label1 $label2 $label3 $label5 Old $Forwarded NOTJUNK $has_cal \*)] Flags permitted.
* 7247 EXISTS
* 0 RECENT
* OK [UIDVALIDITY 1291740963] UIDs valid
* OK [UIDNEXT 158406] Predicted next UID
* OK [HIGHESTMODSEQ 190086] Highest
1 OK [READ-WRITE] Select completed (0.010 + 0.000 + 0.009 secs).

ご覧のとおり、HIGHESTMODSEQ は 190086 のままです。しかし、新しい電子メールをたくさん受信しました。

HIGHESTMODSEQ が増加しない原因は何でしょうか?

Answer 1

IMAPサーバーがMODSEQを増加させるかどうかをテストする方法を知っていますか？

次の論理的なステップは手動で接続して

1. (期待され、宣伝されている) CONDSTORE 機能が利用できない場合にエラーを生成するコマンドに固執します。
2. テストされたアクションの前後で繰り返し要求された場合に、どのアクション (メッセージの受信、Thunderbird のドラッグ アンド ドロップを使用したフォルダー間のメッセージの移動、、の実行doveadm indexなど)が Dovecot によって報告される をdoveadm force-resync増加させ、どのアクションが増加させないかを確認します。HIGHESTMODSEQSELECT

このような：

# openssl s_client -quiet -crlf -connect [::1]:993
* OK [CAPABILITY IMAP4rev1  .. AUTH=LOGIN ..] Dovecot (Debian) ready.
A LOGIN [email protected] password
A OK [CAPABILITY IMAP4rev1  .. CONDSTORE QRESYNC ..] Logged in
A ENABLE CONDSTORE QRESYNC
* OK [HIGHESTMODSEQ 1337] Highest
* ENABLED CONDSTORE QRESYNC
A OK ENABLED (..).
A SELECT INBOX (CONDSTORE)
...
* OK [HIGHESTMODSEQ 1338] Highest
A OK [READ-WRITE] SELECT completed (..).
A SELECT INBOX (CONDSTORE)
...
* OK [HIGHESTMODSEQ 1400] Highest
A OK [READ-WRITE] SELECT completed (..).

IMAPレベルで問題がすでに存在していることを確認したら、そのレベルで作業を続けることができます。あるいは、190086という数字がどこから来ているのかを正確に調査することもできます。私は、Dovecotがアクセスできなくなったために更新できないものを指す数字を誤って報告しているというエッジケースを考えています。インデックスファイルのテキスト表現を読むと、メッセージにたどり着きます。そのメッセージにIMAPフラグを追加すると、doveadm mailbox status -u [email protected] all NewlyCreatedFolderdoveadm dump -t index /file/path/to/mailbox/dovecot.index | grep -B 10 -A 100 "modseq.*190086"いくつかの結果は、問題の本質を示している可能性があります。

Answer 2

今は再び動作します。 を使用して maildir (1 つしかありません) を再作成しmaildirmake、メッセージを元に戻しました。ご協力ありがとうございました。