dovecot/templates/default/conf.d/90-acl.conf.erb

##
## Mailbox access control lists.
##

# vfile backend reads ACLs from "dovecot-acl" file from mail directory.
# You can also optionally give a global ACL directory path where ACLs are
# applied to all users' mailboxes. The global ACL directory contains
# one file for each mailbox, eg. INBOX or sub.mailbox. cache_secs parameter
# specifies how many seconds to wait between stat()ing dovecot-acl file
# to see if it changed.
plugin {
  #acl = vfile:/etc/dovecot/global-acls:cache_secs=300
}

# To let users LIST mailboxes shared by other users, Dovecot needs a
# shared mailbox dictionary. For example:
plugin {
  #acl_shared_dict = file:/var/lib/dovecot/shared-mailboxes
}