the SSL certificate http-request response is invalid due to an invalid certificate error (we should catch this as an exception and log it instead or maybe be a bit more verbose to the user why this happens), I added:
curl_setopt ($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt ($ch, CURLOPT_SSL_VERIFYPEER, 0);
to the file wpmandrill/lib/mandrill.class.php after line 429, solved my problem. ?? I applied this on my dev env, I will check again once I deploy the original mandrill plugin on production to make sure it works there as expected.
