This is a fork of an official library - bitbucket.org/mailchimp/mandrill-api-php.
It supports SSL verification.
composer require petrvacha/mandrill-api-php-ssl
$yourKey = "yourSecretMandrillKey";
$mandrill = new Mandrill($yourKey);
Download cacart.pem from curl.haxx.se/docs/caextract.html.
$yourKey = "yourSecretMandrillKey";
$absolutePathToCaCert = "/etc/ssl/certs/cacert.pem";
$mandrill = new Mandrill($yourKey, $absolutePathToCaCert);