When your booking engine or online store sends email through an API, nobody is looking at a campaign dashboard. Messages go out one by one, triggered by customers. That makes monitoring more important, not less: if confirmations silently start bouncing or landing in junk, you may only find out when a guest arrives at the dock without the details they needed.
The statistics that matter for API email
| Statistic | What it means | Typical action |
|---|---|---|
| Accepted / sent | Mailpro received and processed the request | If requests fail, check your API key and payload |
| Delivered | The recipient’s mail server accepted the message | Your baseline health measure |
| Hard bounce | The address does not exist | Flag it in your system and ask the customer to correct it |
| Soft bounce | Temporary problem, such as a full mailbox | Usually retried; watch for repeats |
| Opens and clicks | Engagement with the message | Useful for pre-arrival and payment emails |
| Complaints | The recipient marked it as spam | Review content and sending frequency |
The FAQ on delivery status for transactional email defines each status in detail.
Push events into your own system with webhooks
Rather than checking a dashboard, let the data come to you. Mailpro webhooks send an HTTP request to your application when an event occurs. Examples from Vincentian use cases:
- A villa booking system marks a reservation “contact needed” when the confirmation hard-bounces, so staff phone the guest.
- A credit union’s portal records that a statement notification was delivered, which helps when a member says they never received it.
- An online store in Kingstown triggers an SMS to a +1 784 number if an order email bounces.
See the three types of Mailpro webhooks for what each event contains.
Reading opens carefully
Open tracking relies on images loading. Some mail apps, notably Apple Mail with Mail Privacy Protection, load images automatically, which inflates opens; others block images, which hides them. Treat opens as a rough signal and rely on delivery, clicks and actual customer actions for decisions.
Watch trends, not single messages
For a small business, a few dozen API emails a day is normal. A single bounce means little; a steady rise in bounces or a sudden drop in delivery to one provider, for example Outlook addresses, points to a real problem. Check weekly, and immediately after changing anything in your sending set-up, such as DNS records or a new sending domain.
Common causes of problems
- Missing or broken SPF, DKIM or DMARC records after a website move.
- Typos in addresses captured at a busy front desk or on a phone keyboard.
- Promotional content inside transactional emails, which can trigger filters.
- Sending from a free webmail address rather than your own domain.
Our guide to email deliverability covers each of these in depth.
Combine statistics with SMS for critical messages
For messages that really must get through, such as a change to a pick-up time or a hurricane-related cancellation, use the statistics to decide on a fallback. If an email is not delivered within a set time, or bounces, your application can send a short SMS instead. Mailpro handles both channels from one account, so a single integration can cover the whole process.
Data and privacy
Statistics are personal data when they relate to identifiable people. Mailpro stores them in Switzerland, outside US jurisdiction, and never sells or rents them, which is helpful when your customers include Europeans covered by GDPR.
For more on the API itself, see the email API overview for SVG, or compare it with SMTP statistics if you send through a relay.