Mailchimp integration

I have install the mailchimp plugin for my multisite, however, when I test by signing up new user, after I click the link from my email to varify the account, it show me this error on the top of my site.

Warning: MailChimp listSubscribe() Error: 214 – is already subscribed to list AntiqueTalker. Click here to update your profile. in /home/antitalk/public_html/wp-content/plugins/mailchimp-sync/mailchimp-sync.php on line 106

Need some help here.