It is not required for initial support of MIX, but will be a nice addon.

I moved it to next version (either 8.3.0 or 9.0.0, we will see). But it would be good to create dedicated tasks for particular parts of the XEP as it consists of various functionalities - please do so.

As per our conversation - it would be nice to improve the xep regarding 4. Retracting a Message and leverage existing mechanisms (XEP-0424: Message Retraction) instead of custom payloads.

@wojtek As I've asked about that on standards mailing list, there response was that this could be updated:

I think it makes sense to update 407 to use and reference 424

so it might be good to submit a PR for this XEP.

I made some changes in XEP-0407 and referenced xep-0424 - I think it looks ok. @andrzej.wojcik Please do take a look https://github.com/tigase/xeps/commit/e4d19fef9d479fac7344e1763d73d8a7fedd445d and if it's ok I'll submit PR to XSF.

@wojtek Just one suggestion, with XEP-0424 it is possible to have a working retraction even without support from the MIX channel as MIX "storing and forwarding" message retraction request would forward that to the client and the client would remove it on its own. Sure, that will not remove a message from the archive of the MIX channel or from the user's MAM archive of the channel but would indicate to the user that message was retracted and could remove it from the user's local storage.

Except for that, it looks OK.

PR submitted: https://github.com/xsf/xeps/pull/1047