Sending and personalising transactional emails

Every transactional API call includes the full HTML of your email directly in the request body. This gives you complete control over the content and structure of each message your application sends.

How it works

You pass the HTML (and optionally plain text) directly in the API request body. Your application builds the email content dynamically and includes it in each request.

Personalisation

Personalisation lets you insert dynamic values into your email— the recipient's first name, an order number, a product name, a price. You define placeholders in your HTML and pass the corresponding values in the API call.

The exact placeholder syntax and the API parameters for passing variable values are documented in the Flexmail Email API documentation at email-api.flexmail.eu/documentation, under the Personalisation sections.

Common personalisation variables

Typical variables used in transactional emails include:

• Recipient name (first name, full name)
• Order or reference number
• Product names and quantities
• Prices and totals
• Dates and deadlines
• Confirmation or reset links
• Account-specific URLs or codes

Testing personalisation

Before going live, test your email with realistic variable values to make sure all placeholders resolve correctly. The API documentation includes guidance on sending test messages with custom variable values.

Check in particular that:

• All placeholders are replaced — no raw variable syntax appears in the delivered email.
• Fallback values display correctly when an optional variable is not passed.
• Links resolve to the correct URLs after variable substitution.

Next steps

• See "Getting started with the transactional API" for account setup and first send.
• See "Transactional webhooks" to track delivery and engagement for your sends.