data
Personalisation values
Values substituted into {$name} placeholders in the subject, the addresses and the body — and the switch that turns substitution on at all.
In detail
Present, and the engine replaces placeholders from it, automatically adding envelope and recipient to what is available. Absent, and nothing is substituted — which is the documented way to send a message whose body legitimately contains curly braces. For us the interesting part is what it saves: personalising inside MailerQ means one template travels per message instead of a fully rendered body, which matters when the same campaign goes to a large list. Hub currently renders everything before sending, so this is an option rather than a practice — and it interacts with our spintax, which is expanded at send time on our side.