The Growth team has always desired to use email to engage newcomers outside the wiki. The parent epic under which this one is nested leads to all the preliminary work and thinking that the team has not executed on. This project page also describes our thinking: https://www.mediawiki.org/wiki/Growth/Personalized_first_day/Engagement_emails

In this epic, the Communications department is planning a first attempt with "welcome emails", sent to newcomers after their accounts are created. They'll opt in to receiving these emails when they create their accounts, and the Growth team will export lists to the Communications department to send via MailChimp.