title: MailChimp: Bulk re-send opt-in mailout to all subscribers
body: <p>A client of mine is planning to move from a WordPress newsletter plugin to MailChimp. </p>
  
  <p>As a result we'd be importing all the subscribers from the old system into MailChimp. However we have a feeling that a lot of those subscribers are either fake, dead emails, or not interested any more.</p>
  
  <p>I was wondering whether there is any way to bulk resend an opt-in, so that all subscribers get a mail asking them to click a link to continue their subscription?</p>
  
  <p>I didn't notice anything obvious when selecting all subscribers in a list on MailChimp</p>