Are you aware of a federated, decentralized approach to e2ee messaging that doesn't require trusting the servers? i.e., without the metadata leakage of email, x

Are you aware of a federated, decentralized approach to e2ee messaging that doesn't require trusting the servers? i.e., without the metadata leakage of email, xmpp, Matrix, etc.? The only options I know of have poor support for offline messaging (and kill the battery) due to being peer-to-peer. I'm not yet aware of any federated approaches that prevent a server from connecting a sender and recipient, but would love to be educated otherwise.