I set up Jami on my Android Phone, also talked 3 other people into doing the same on their Android phones.
We all set up Jami using defaults.
I also Linked in my Linux Mint Laptop as a second client. Only defaults enabled.
We have communicated via email to confirm we are actually on line.
The others have sent me messages, I have not received those messages.
I have messaged them, they have not received those messages.