mod_isolation: Isolate virtual hosts from each other
The module blocks communication of users between different virtual hosts.
Configuration
The module doesn't have any options, so the simplest way to configure is:
modules:
mod_isolation: {}
Hint: if you also want to block whole s2s, use built-in ejabberd's s2s_access option:
s2s_access: none
modules:
mod_isolation: {}