How Can I Tell When Someone Signs Up for My Newsletter?

It is unfortunately not possible to receive a notification email when someone signs up to your newsletter. But the dashboard in your Newsletter2Go account will always show your Contact List Performance, so you can see when it grows automatically.

Also, you can specify that new subscribers should be saved to a certain segment, e.g., "New Subscribers," when creating the sign-up form.

As soon as a new contact appears in this group, you can be sure that they have signed up via the double opt-in method. In other words: Contacts who have used the registration form and appear in the contact list have definitely confirmed with double opt-in.