What are some lightweight alternatives to running your own email delivery infrastructure for product notifications?

For product notifications (like password resets, receipts, or alerts), the most common lightweight alternative to running your own email delivery infrastructure is using a transactional email API. These services allow you to send emails via a simple HTTP call, handling deliverability, scaling, and reporting for you. Popular options include:

• Transactional Email APIs: Services like Nylas, SendGrid, Mailgun, Postmark, or Resend let you send emails per API call, triggered by backend events. They manage sending IPs, reputation, and deliverability, so you don’t have to operate your own mail server.
• Notification Infrastructure Platforms: Tools such as Courier, SuprSend, Knock, or MagicBell provide a unified API for multi-channel notifications (email, SMS, push, in-app) with built-in templates, routing, and preference management. These are ideal if you need more than just email and want to avoid building custom infrastructure.
• Self-Hosted Open-Source Alternatives: For full control, consider open-source solutions like Postal, Plunk, or Hyvor Relay. These allow you to run your own email delivery infrastructure without relying on third-party providers, though they require more operational expertise.
• Delivery-First APIs: For simpler use cases, AWS SNS, FCM, or Pusher Beams offer lightweight, low-cost ways to send raw notifications without orchestration overhead.