On April 27, Mandrill became a paid MailChimp add-on. Any Mandrill accounts that weren't linked to a MailChimp account by May 11, 2016 have been disabled and can no longer be accessed. For more information, see this blog post.
To continue using Mandrill, add Mandrill to your MailChimp account.
Need help? Use the Support link inside of your Mandrill account.