Requesting list membership confirmation from subscribers [Solved]

I have a list of previous subscribers. I’d like to upload these to a list on my phplist system. I’d like to send each person on the list one e-mail asking them to confirm their subscription. If they don’t confirm then they should not receive future e-mails.

Is there some way of achieving this from within phplist or if an add-on is required any suggestion would be welcomed.

I’ve done some further research and the plugin I need to do this is phplist-plugin-invite.