I'm not sure what you mean by prefixes. I'm just talking about regular email addresses at the provider's domain(s), like YourEmailName@TheirDomain.com. If you were asking about whether I have found providers that satisfy this requirement (either "lifetime" free email or no recycling of addresses), aside from the big ones that we're trying to avoid, like Google and Microsoft, the only ones I've found so far are Proton (free tier), Runbox (no recycling), and Infomaniak (free tier). I didn't check Tuta since I'm not interested in fully encrypted email providers.

I don't think that we would ever get a provider that would satisfy those stringent requirements you listed, but I figure that anything is better than nothing. No problem, you're welcome, but sorry to bring your attention to that thought.

Edit: added missing word ("free tier" instead of just "free" after Infomaniak)