Question about how to serve many imap users on some mailbox.

[Oleksandr Lystopad]

Hi, dear dovecot users!

I am running 2.2.29.1 (e0b76e3) on FreeBSD.

In my case, one mailbox info at example.com is shared between 5-10 managers.

Sometimes they complains that no new messages displayed in folder message
count list in brackets (bold number if new messages exists), but when they
click on the imap folder (for example Inbox) they could see many new mails.
There not only Inbox folder, they have 10-30 folders with quite big flow of
new messages. Almost all users are using Microsoft Outlook MUA.

Please, help me to solve the issue.


My config could be found bellow (dovecot -n):
auth_failure_delay = 12 secs
auth_mechanisms = login cram-md5 plain
auth_verbose = yes
disable_plaintext_auth = no
first_valid_gid = 26
first_valid_uid = 26
lda_mailbox_autocreate = yes
listen = *
login_greeting = imap/pop mailserver ready
mail_location = maildir:~/Maildir
mail_max_userip_connections = 50
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
passdb {
  args = /usr/local/etc/dovecot/dovecot-sql.conf
  driver = sql
}
protocols = pop3 imap sieve
service auth {
  unix_listener auth-client {
    group = mailnull
    mode = 0600
    user = mailnull
  }
  unix_listener auth-login {
    group = mailnull
    mode = 0600
    user = $default_internal_user
  }
  unix_listener auth-master {
    group = mailnull
    mode = 0600
    user = mailnull
  }
  unix_listener auth-userdb {
    group = mailnull
    mode = 0600
    user = mailnull
  }
  user = root
}
service imap-login {
  inet_listener imap {
    port = 143
  }
  inet_listener imaps {
    port = 993
  }
}
service imap {
  process_limit = 512
}
service pop3-login {
  inet_listener pop3 {
    port = 110
  }
  inet_listener pop3s {
    port = 995
  }
}
service pop3 {
  process_limit = 512
}
ssl_cert = </usr/local/etc/SSL/my.crt
ssl_key =  # hidden, use -P to show it
userdb {
  args = /usr/local/etc/dovecot/dovecot-sql.conf
  driver = sql
}
verbose_proctitle = yes
protocol pop3 {
  pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
  pop3_uidl_format = %08Xu%08Xv
}
protocol imap {
  imap_client_workarounds = delay-newmail tb-extra-mailbox-sep
}
protocol lda {
  mail_plugins = sieve
}