Send out with Mandrill
You need an Mandrill account first.
In your configuration (Magento Admin Panel -> System -> Configuration | eMarketing) under the section Email you can choose Mandrill as a transporter. You will be asked for your username and an API-Key. The extension will try to connect to your system via SMTP.
You can step an optional subaccount id as well if required.
You can also define default tags for your setup and/or add your campaign tags.
Add Metatags will also add recipient based information, such as campaign id, recipient id, variation id.
If everything works you should get a success message after you have saved your changes.