If you give them a real email account as they sign up, they'll have one.
So for example, I want to sign up at tuti.study and you generate a random email address like j9u6iilejixzs3f6ba9k6stoo@tuti.study for me.
Then I would have a real email account. If you want, you could restrict it to sending email to/from the service. You could use Zimbra for it I suppose.
If that isn't good enough, then sorry, I have to suspect you are planning something nefarious.
So for example, I want to sign up at tuti.study and you generate a random email address like j9u6iilejixzs3f6ba9k6stoo@tuti.study for me.
Then I would have a real email account. If you want, you could restrict it to sending email to/from the service. You could use Zimbra for it I suppose.
If that isn't good enough, then sorry, I have to suspect you are planning something nefarious.