diff --git a/install_update_dovecot-2.4.sh b/install_update_dovecot-2.4.sh
index 862b552..b8fbc7a 100755
--- a/install_update_dovecot-2.4.sh
+++ b/install_update_dovecot-2.4.sh
@@ -10179,9 +10179,9 @@ if [[ $dovecot_major_version -gt 2 ]] \
 
    read -r -d '' NEW_BLOCK <<'EOF'
 protocol imap {
-  mail_plugins {
-    imap_acl = yes
-  }
+   mail_plugins {
+      imap_acl = yes
+   }
 }
 EOF
 
@@ -10234,9 +10234,9 @@ namespace shared {
    prefix = shared/$user/
 
    # Mail location setting
-   mail_home = /var/vmail/%{user | domain}/%{user | username}
    mail_driver = maildir
-   mail_path = ~/Maildir
+   mail_path = %{owner_home}/Maildir
+
    mail_index_private_path = ~/Maildir/shared/%{owner_user}
 
    # Use the default namespace for saving subscriptions.
@@ -10273,6 +10273,27 @@ ${NEW_BLOCK}
 EOF
    fi
 
+   read -r -d '' NEW_BLOCK <<'EOF'
+acl_sharing_map {
+   dict file {
+       path = /var/vmail/shared-mailboxes.db
+   }
+}
+EOF
+
+   if grep -qE "^\s*acl_sharing_map\s+{" "${_conf_file}"; then
+
+      replace_code_block "acl_sharing_map" "${NEW_BLOCK}" "${_conf_file}" || _failed=true
+
+   else
+       cat <<EOF >> "${_conf_file}" || _failed=true
+
+# A shared mailbox dictionary that defines which users may LIST mailboxes shared by other users.
+${NEW_BLOCK}
+EOF
+
+   fi
+
 
    if ! $_failed ; then
       echo -e "$rc_done"