"To mitigate this problem SimpleX Messaging Protocol servers support 2-hop onion message routing when the SMP server chosen by the sender forwards the messages to the servers chosen by the recipients, thus protecting both the senders IP addresses and sessions, even if connection isolation and Tor are not used."
The thing is, like I said, there are only two main companies running all the servers. Akamai and RunOnFlux. So unless Tor is used, it's a 50-50 chance that both users are connecting on to servers run by Akamai. Doesn't matter if the two servers don't share with each other the information about the IP-adderss of the user's peer. It's enough the parent VPS company has access to all traffic coming into the infrastructure. There's nothing "onion" about that routing. It's much closer to just traffic between two nodes of a server farm. Which is what practically any scalable IM server does.
"To mitigate this problem SimpleX Messaging Protocol servers support 2-hop onion message routing when the SMP server chosen by the sender forwards the messages to the servers chosen by the recipients, thus protecting both the senders IP addresses and sessions, even if connection isolation and Tor are not used."
The thing is, like I said, there are only two main companies running all the servers. Akamai and RunOnFlux. So unless Tor is used, it's a 50-50 chance that both users are connecting on to servers run by Akamai. Doesn't matter if the two servers don't share with each other the information about the IP-adderss of the user's peer. It's enough the parent VPS company has access to all traffic coming into the infrastructure. There's nothing "onion" about that routing. It's much closer to just traffic between two nodes of a server farm. Which is what practically any scalable IM server does.