I know Prosody does & I’d put money on ejabberd supporting it too but I’ve not looked it up. You can check compliance for Conversations using https://compliance.conversations.im/ which includes message archive management + carbons or use a client that exposes a servers supported XEPs. Yes, it works with encrypted messages.
Asymmetric communication allows communication when one party is offline. One of the biggest issues with XMPP is both parties need to be online…
https://xmpp.org/extensions/xep-0203.html
I’ve not yet had issues with messages not getting delivered when recipient is offline.
Which server do you use that caches messages for you, and how do I know if a given XMPP provider has implemented this functionality?
Also, does it also work with e2ee messages?
I know Prosody does & I’d put money on ejabberd supporting it too but I’ve not looked it up. You can check compliance for Conversations using https://compliance.conversations.im/ which includes message archive management + carbons or use a client that exposes a servers supported XEPs. Yes, it works with encrypted messages.