Opt-in email

Opt-in email is a term used when someone is not initially added to an emailing list and is instead given the option to join the emailing list. Typically, this is some sort of mailing list, newsletter, or advertising. Opt-out emails do not ask for permission to send emails, these emails are typically criticized as unsolicited bulk emails, better known as spam.

This keyword could refer to multiple things. Here are some suggestions: