If you use a double opt in procedure for adding subscribers to your list you may see them listed as Pending in your subscriber database. These subscribers have not clicked on the link in the activation e-mail the system sent them.
You may need to resend them the activation e-mail.
1. Click on the Subscribers tab.
2. Click More options by the search field on top of the page.
3. Select opt-status Pending in the drop down box.
4. Click Search.
5. All pending subscribers (if any) will be listed below.
6. Click on a subscribers e-mail address.
7. In the View Subscriber page click on the send reminder-link to resend your Activation reminder e-mail to that specific subscriber.