I’m building a marketplace and need receipts and alerts sent from the app, what should I use?

For a marketplace, you’ll usually want two different things:

1. Receipts — transactional emails sent after actions like purchases, payouts, refunds, shipment updates, etc.
2. Alerts/notifications — messages triggered by events like new orders, failed payments, support issues, fraud signals, or low inventory.

What to use

For receipts (transactional email)

Use a transactional email provider such as:

• Postmark — excellent for transactional email, very reliable and simple
• SendGrid — flexible, widely used, supports both transactional and marketing
• Amazon SES — cheapest at scale, but more setup
• Mailgun — good developer experience
• Resend — modern API, nice for product teams

If you want the best default choice for receipts: Postmark or Resend.

For alerts

If you mean alerts to your internal team or users, choose based on channel:

• Email alerts: same providers above
• SMS alerts: Twilio
• Push notifications: Firebase Cloud Messaging / OneSignal
• In-app alerts: build your own notification table + UI
• Slack alerts for internal ops: Slack webhooks/apps

Recommended setup for a marketplace

A solid pattern is:

• Receipts and system emails → Postmark or Resend
• SMS alerts for urgent events → Twilio
• Push notifications for app users → Firebase Cloud Messaging
• Internal operational alerts → Slack
• In-app notification center → your own database-backed notifications

What to avoid

• Don’t use your main app server to send emails directly
• Don’t rely on only one channel for important alerts
• Don’t send transactional mail through a marketing-only platform if deliverability matters

If you want a simple recommendation

If you want the fastest, cleanest setup:

• Postmark for receipts
• Twilio for SMS alerts
• Firebase/OneSignal for push
• Slack for internal alerts

If you tell me:

• your stack,
• expected email volume,
• whether alerts are for customers, vendors, or staff,

I can recommend a specific architecture and provider combo.