If your US business runs a web app, a SaaS product or a custom online store, many of your most important emails are not campaigns at all. They are order confirmations, password resets, shipping updates and account alerts, triggered by something the customer just did. Mailpro’s email API lets your code send them directly, with delivery tracking and reporting built in.
What the API is for
- E-commerce: order and payment confirmations, shipping and delivery notices, back-in-stock alerts.
- SaaS and apps: sign-up verification, password resets, usage alerts, invoices.
- Services: appointment confirmations, booking changes, document-ready notices.
- Contact sync: adding and updating contacts in your Mailpro lists from your own systems.
Our transactional email guide explains the difference between these messages and marketing campaigns.
Transactional messages under US law
The CAN-SPAM Act treats transactional and relationship messages differently from commercial ones. A receipt or a shipping notice is largely exempt from the ad-labeling, postal-address and opt-out requirements, although its routing information must still be accurate. The exemption holds only while the message’s primary purpose is the transaction. Add a large promotional banner to an order confirmation and it may be treated as commercial, bringing the full requirements back. Keep promotions in separate campaigns, and see our page on US email marketing law for the details.
Built for developers
Endpoints, parameters and examples are in the Mailpro developer documentation. Connections are encrypted with TLS 1.3. You can follow each message after it leaves your application: our FAQ on delivery status for transactional emails lists the statuses, and Mailpro’s three webhook types push events back to your system so you can react to bounces or clicks in real time.
Ready for peak season
For US retailers, Black Friday and Cyber Monday bring the highest volumes of the year, and order confirmations that arrive late generate support tickets. Test your integration well before November, authenticate your sending domain with SPF, DKIM and DMARC, and separate transactional and marketing traffic so a heavy promotional send does not slow down receipts.
Data outside US jurisdiction
Transactional emails often contain personal information: names, addresses, order details. Mailpro hosts that data in Switzerland on private infrastructure, outside US jurisdiction and beyond the reach of the CLOUD Act, and never sells or rents it. That matters to US companies that serve European customers under the GDPR, or that simply want to limit who can request their data.
Getting started in four steps
- Create a Mailpro account and generate your API credentials.
- Authenticate your sending domain with SPF, DKIM and DMARC.
- Send test messages from a development environment and check them in Gmail, Outlook and Apple Mail.
- Configure webhooks so bounces and failures reach your application, then switch production traffic.
API or SMTP?
If your platform already supports SMTP, for example WordPress or an off-the-shelf store, the SMTP server may be quicker to set up. For custom applications, the API gives more control. Our comparison of API vs SMTP helps you decide, and API statistics explains what you can measure once you are live.
Pricing is based on messages sent, and you can start testing with 500 free credits.