I don't remember well how email works and I'm not in contact with riseup, but often a provider will send a bounce message back.

Like cock.li, the riseup folks try to do the right thing. But their warrant canary system did reveal that the FBI forced their hand around 2016.

I haven't received emails from you =/ email is kind of silly in its insecurity, anyway.

It's confusing to be a software developer who does not develop software. The email problems should be easy to solve for ones who do.