Thank you for reaching out to the Constant Contact Community. It's my pleasure to assist you today.
I'm sorry that you are experiencing a problem with contacts stuck in Awaiting Confirmation. In order to send the confirmation email again, you will need to turn on the Confirmed Opt In feature, then add the contacts email address again via the Sign Up Form URL. This should trigger the email to go back out and allow them to be added as active contacts to the list. After you have completed the task and the emails have been added to the list, you can turn off the confirmed opt in feature if you don't want to continue with it.
Please feel free to reach out if you need anything else. Thank you for choosing Constant Contact. Have a great day!