Merge tags and fallbacks

Merge tags pull from contact fields. The common ones:

• {{first_name}}, {{last_name}}
• {{email}}
• {{custom.company}} and any custom field you define
• {{unsubscribe_url}} (required, validated on save)
• {{web_version_url}}

Always set a fallback: {{first_name | there}} renders "there" when the field is empty. "Hi there," beats "Hi ," every time.