mod_block_strangers and ACL

Question

My ejabberd version is 19.08. Could you advice or explain, why

mod_block_strangers:
  access: list
  drop: true

access_rules:
  list:
    allow: all

works fine?

But such:

mod_block_strangers:
  access: list
  drop: true

access_rules:
  list:
    allow: admin

Don't work? This example is without syntax, in my config it's okay. Why acl "all" works fine and other acl in mod_block_strangers doesn't work? Even "admin" acl

Answer 1

This configuration allows admins sending to strangers, and denies non-admins sending to strangers:

access_rules:
  list:
    allow: admin
    deny: all

modules:
  mod_block_strangers:
    allow_local_users: false
    access: list
    drop: true