Every application that sends email has to choose how to hand messages over: through SMTP, the protocol email has used for decades, or through an HTTP API. Both work with Mailpro. The right choice depends on what you are building, who maintains it and what you need to know after each message leaves.
The short version
| SMTP relay | Email API | |
|---|---|---|
| Set-up | Change host, port and credentials in existing software | Write code against HTTP endpoints |
| Best for | WordPress, store platforms, ERPs, legacy systems | Custom apps, SaaS products, microservices |
| Statistics | Available in the Mailpro dashboard | Available in the dashboard and programmatically |
| Contact management | Separate | Can be automated in the same integration |
| Event data | Dashboard | Webhooks to your own endpoint |
When SMTP is the better choice
A large share of Indian small businesses run on off-the-shelf software: a WooCommerce store, a school management system, an accounting package that emails GST invoices, or a hospital appointment system. These tools almost always support SMTP. Pointing them at Mailpro’s SMTP server takes minutes and needs no developer. It is also the natural option when your IT partner maintains the system and you do not want to change its code.
Read what is SMTP if you want a refresher on how the protocol works.
When the API is the better choice
If you are building your own product, as many Indian start-ups and IT firms do, the API offers more control:
- Send transactional emails and automated sequences directly from your code.
- Add contacts to lists and segments as users sign up or change plans.
- Pull delivery and engagement statistics into your own dashboards.
- Use webhooks to react to bounces immediately, for example by asking a user to fix a mistyped address.
- Insert personalised content generated by your system.
Scenarios from Indian businesses
A D2C brand on a hosted store platform
SMTP for order and shipping emails from the store; Mailpro’s campaign tools for newsletters. No custom code needed.
A lending or payments app
API for OTP emails, statements and alerts, with webhooks recording delivery against each transaction. Marketing goes out separately, only to users who consented.
A B2B SaaS company serving global clients
API for sign-up and product emails, with statistics by country to compare Indian and overseas users. SMTP for internal tools such as the helpdesk.
A coaching institute
SMTP from its student management software for fee receipts; campaigns from the Mailpro dashboard for admission season.
Things that matter whichever you choose
- Authenticate your domain with SPF, DKIM and DMARC so Gmail and other providers trust your messages.
- Separate transactional and marketing streams. Mixing offers into service messages hurts deliverability and blurs the consent position under the Digital Personal Data Protection Act 2023.
- Protect credentials. Store SMTP passwords and API keys in a secrets manager, not in code repositories.
- Know where data goes. Mailpro uses TLS 1.3 in transit and hosts data in Switzerland, outside US jurisdiction. See our GDPR compliance page if you also serve European customers.
You can use both
Many teams do: SMTP for packaged software, the API for their own product. Both draw on the same Mailpro account and credits. Explore the email API for India or compare approaches in our blog post on SMTP relay vs email API.
Developer resources
See the API documentation, the webhooks reference and the SMTP and API FAQ.