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
I just used a temp email service to make several proton accounts for different things but last time I tried they didn’t let me but that may have been some other issue