张工，按照你的回复，我查了一下，找到了“Share IMAP Folder" 的文档(http://www.iredmail.org/wiki/index.php?title=IRedMail/FAQ/Share.IMAP.Folder)，并按照文章的内容设置dovecot.conf文件
protocol lda {
    mail_plugins = ... acl
}

protocol imap {
    mail_plugins = ... acl imap_acl
}
但是在用测试时，出现错误，显视如下：
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE START
TLS AUTH=PLAIN AUTH=LOGIN] Dovecot ready.
. login zy.kjk@domain.org 888
. OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT
SORT=DISPLAY THREAD=REFERENCES THREAD=REFS MULTIAPPEND UNSELECT CHILDREN NAMESPA
CE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES W
ITHIN CONTEXT=SEARCH LIST-STATUS QUOTA ACL RIGHTS=texk] Logged in
. setacl Sent zy.yaoming@domain.org rli
. BAD Error in IMAP command SETACL: ACLs disabled.
显视ACLs disabled,并且我发现这样设置后，发送的邮件在“已发送列表”中不显视。
文档显视的是在dovecot 1.2下，而我用的是dovecot 2.0.8,是不是版本的问题。我也查看了
Mailbox sharing between users（http://wiki2.dovecot.org/SharedMailboxes/Shared），但是它与Share IMAP Folder存在很大的区别，请问在dovecot 2.0.8下怎样Share IMAP Folder.

张工，还是不行。好像dovecot 2.0.8 不支持这样设置。然后我接照官方的文档，做了如下设置。
更改dovecot.conf,如下：

plugin {
...
    acl = vfile
    acl_shared_dict = proxy::acl
}

dict {
   ....
    acl = pgsql:/etc/dovecot/dovecot-dict-sql.conf.ext
}

protocol imap {
       .....
        mail_plugins = ... acl imap_acl
}

namespace {
    type = private
    separator = /
    prefix =
    inbox = yes
    # location defaults to mail_location.
}

namespace {
    type = shared
    separator = /
    prefix = Shared/%%u/
    location = maildir:/%%Lh/Maildir/:INDEX=/%%Lh/Maildir/Shared/%%u
    # this namespace should handle its own subscriptions or not.
    subscriptions = no
    list = children
}

新建dovecot-dict-sql.conf.ext
connect = host=127.0.0.1 dbname=vmail user=vmailadmin password=BG4synv3KJLV0OMq9lgjMkHEx0UW9R
map {
  pattern = shared/shared-boxes/user/$to/$from
  table = share_folder
  value_field = dummy

  fields {
    from_user = $from
    to_user = $to
  }
}

在用命令setacl Sent to@damin.org rli 时，它显视成功，但是在vmail 的share_folder
表中，没有记录。查看dovecot.log,有如下错误。
Jan 04 11:25:16 dict: Error: pgsql(127.0.0.1): Connect failed to database vmail: could not connect to server: Connection refused
Jan 04 11:25:16 dict: Error:     Is the server running on host "127.0.0.1" and accepting
Jan 04 11:25:16 dict: Error:     TCP/IP connections on port 5432?
Jan 04 11:25:17 dict: Error: pgsql(127.0.0.1): Connect failed to database vmail: could not connect to server: Connection refused
Jan 04 11:25:17 dict: Error:     Is the server running on host "127.0.0.1" and accepting
Jan 04 11:25:17 dict: Error:     TCP/IP connections on port 5432?
Jan 04 11:25:17 dict: Error: pgsql(127.0.0.1): Connect failed to database vmail: could not connect to server: Connection refused
Jan 04 11:25:17 dict: Error:     Is the server running on host "127.0.0.1" and accepting
Jan 04 11:25:17 dict: Error:     TCP/IP connections on port 5432?
Jan 04 11:25:17 dict: Error: pgsql(127.0.0.1): Connect failed to database vmail: could not connect to server: Connection refused
Jan 04 11:25:17 dict: Error:     Is the server running on host "127.0.0.1" and accepting
Jan 04 11:25:17 dict: Error:     TCP/IP connections on port 5432?
Jan 04 11:25:22 dict: Error: pgsql(127.0.0.1): Connect failed to database vmail: could not connect to server: Connection refused
Jan 04 11:25:22 dict: Error:     Is the server running on host "127.0.0.1" and accepting
Jan 04 11:25:22 dict: Error:     TCP/IP connections on port 5432?
Jan 04 11:25:22 dict: Error: pgsql(127.0.0.1): Connect failed to database vmail: could not connect to server: Connection refused
Jan 04 11:25:22 dict: Error:     Is the server running on host "127.0.0.1" and accepting
Jan 04 11:25:22 dict: Error:     TCP/IP connections on port 5432?
Jan 04 11:25:22 dict: Error: pgsql(127.0.0.1): Connect failed to database vmail: could not connect to server: Connection refused
Jan 04 11:25:22 dict: Error:     Is the server running on host "127.0.0.1" and accepting
Jan 04 11:25:22 dict: Error:     TCP/IP connections on port 5432?

请问是什么原因，是我那里设置不对吗？我是完全按官网上的文档来的啊，张老大帮帮忙，给看看。