mod_offline
does not take into account XEP-334 tags.
This module will not add to the offline storage those messages tagged
with <no-store />
.
First copy the module to the prosody plugins directory.
Then add “offline_hints” to your modules_enabled list in your configuration.
No configuration options are available.
With the plugin installer in Prosody 0.12 you can use:
sudo prosodyctl install --server=https://modules.prosody.im/rocks/ mod_offline_hints
For earlier versions see the documentation for installing 3rd party modules