MailMachinePRO Mailing List Manager
MailMachinePRO XT contains all the functionality of MailMachinePRO plus advanced email marketing features such as:

Event Triggers: Send emails or perform actions based on a subscriber's date field or when a recipient opens an email or clicks a link.

Conditional Logic Personalization: Personalize emails with logic statements to change content based on your rules.

See the features page and features description page for additional information.