The issue I’m seeing with any free plans of email providers is that they either require an identifying verification, or don’t allow the email to be used for services.
tutamail, for example, states that the free plan is not to be used to signup for services.
protonmail requires verification by email ‘to prove you are human’.
Thank you
Just… don’t. Tuta is probably fine for paid services but they’re well known for nuking free accounts for various reasons. And they might not enable you to send/receive from a free account to begin with - Last time I attempted to create a free account there, then asked support if they could enable me to be able to send/receive some emails, instead of responding they simply nuked my new free account.