I installed the plugin and configured it as shown in the documentation (added API key and enabled the plugin). I even configured the DKIM and SPF records at the Mandrill backend. But Joomla refuses to send the mails via Mandrill. The moment I disable the plugin, the mails go fine via the usual server. I'm running the latest version (3.0.2) on Joomla 2.5.20.
Looking forward to your assistance.