Emails after Registration

Hello everyone,

Does anybody know of a good plugin that sends individual emails 3 or more days after users register?

I have a website where Gravity Forms is a must, because it registers my users and it already handles the welcome emails and the admin emails pretty well.

What I need is a plugin that after 3 days of each registration, it would send an email to any newly registered users, saying something like:
“Hi, we haven’t seen you for a while…”

Any thoughts?