Are you building, or maybe own, a billing and invoicing platforms?
We’re sure you understand the emails your application sends are critical for the user experience, from delivering a new invoice and confirming a payment to sending a password reset link. A stable, reliable email API is the backbone of these systems, ensuring that every financial transaction is followed by a clear, timely, and secure communication.
The right email API for your billing platform must tick all of the boxes below:
- Be able to handle scale
- Manage potential failures
- Integrate seamlessly with your existing tech stack
- Handle a variety of tasks (including delivering PDFs)
- Support custom templates
- Providing real-time event tracking
Check how to find them and which platforms pass with flying colors.
Key features of an email API for invoicing
When you’re building a platform that handles user finances, the stakes are high. Choosing an email API that can keep up with the demands of an invoicing system requires careful consideration of several key features:
- Reliable delivery & uptime: An invoice that doesn’t reach the customer is a payment that might not get made. Your email API must guarantee high deliverability and offer a robust uptime SLA (Service Level Agreement) to ensure critical messages are never lost.
- API performance & webhooks: A fast, high-performing API is essential for real-time applications. Webhooks are equally important for receiving instant notifications about events like bounces, opens, or link clicks, allowing your application to update a user’s subscription status or billing cycle automatically.
- Template & attachment support: Billing apps require dynamic, branded emails. A good email API should offer a powerful templating system that allows you to easily personalize emails with customer data. Support for attaching PDFs directly via the API is a must-have feature for sending invoices and receipts.
- Bounce & event tracking: A comprehensive logging and tracking system is non-negotiable. You need to know when an email fails to deliver, why it bounced, or if a payment reminder has been read. This data is vital for customer support and for improving your communication workflows.
- Developer SDKs & platform integrations: The right API should offer comprehensive SDKs for various programming languages, making it simple for your development team to integrate it into your application.
Leading email API providers for billing platforms
SendGrid
As one of the leaders in the email space, SendGrid offers a comprehensive platform. It provides good API support, making it easy to integrate with any billing platform. Its robust templating engine, combined with detailed logging and analytics, makes it a go-to choice for scaling invoice delivery to a large customer base.
Mailgun
Mailgun has a clean API and FinTech-ready features. It excels at handling PDF attachments and offers a clean templating engine for creating dynamic invoices. Its strong webhook support is particularly useful for billing platforms that need to track email events in real time to manage subscriptions and customer accounts.
Mailtrap
Mailtrap provides a reliable and secure sending API designed to handle your most critical transactional emails. Its core focus on high deliverability, security, and real-time logging makes it an excellent choice for a billing platform handling sensitive customer data.
With its dedicated IP options and robust infrastructure, Mailtrap’s API ensures that your invoices and payment notifications always reach their destination.
For any SaaS startup, setting up a free SMTP server with Mailtrap is an excellent first step toward building a reliable email infrastructure.
Brevo (ex-Sendinblue)
Brevo is a versatile platform that combines transactional and marketing email features. It’s often a good choice for startups on a budget. With its simple-to-use API, drag-and-drop email builder, and reliable delivery, it can easily handle the basic needs of a new invoicing SaaS.
Postmark
Postmark is a highly specialized transactional email provider known for its exceptional speed. For time-sensitive communications like payment confirmations and receipts, its fast delivery can significantly improve the user experience. Its minimalist feature set makes it a powerful and reliable choice for developers who prioritize speed and reliability above all else.
Feature comparison
| SendGrid | Mailgun | Mailtrap | Brevo | Postmark | |
|---|---|---|---|---|---|
| PDF Support | ✓✓✓ | ✓✓✓ | ✓✓ | ✓✓ | ✓✓ |
| Deliverability | ✓✓ | ✓✓ | ✓✓✓ | ✓ | ✓✓✓ |
| Event Webhooks | ✓✓✓ | ✓✓✓ | ✓✓ | ✓ | ✓✓ |
| Template Support | ✓✓✓ | ✓✓ | ✓✓ | ✓✓ | ✓ |
Final thoughts
The right email API can make or break the user experience for your billing or invoicing platform.
For developers and teams building with a security-first mindset, a reliable and secure sending solution like Mailtrap is a perfect fit.
If your primary focus is on blistering speed for time-sensitive notifications, Postmark offers unmatched performance.
Ultimately, the best choice depends on the specific needs of your application and your development team. It’s best to explore the APIs firsthand to see which one fits your unique workflow.
