per license. If you need MailWizz on multiple servers, you must purchase a separate license for each. Managing Your License Key Installation
MailWizz license key (also referred to as the Item Purchase Code mailwizz license key
The Mailwizz license key is tied to your specific installation of Mailwizz, which means you can only use it on one domain or installation. If you need to use Mailwizz on multiple domains or installations, you'll need to purchase a separate license key for each one. per license