What should I use for transactional email and SMS delivery?

For transactional email and SMS delivery, the best choice depends on what you value most: reliability, deliverability, ease of integration, cost, and global coverage. Here are the most common strong options:

Good default picks

Email

• Postmark — excellent for transactional email, very high deliverability, simple API, great for receipts, password resets, alerts.
• SendGrid — widely used, flexible, good ecosystem, but can be more complex.
• Amazon SES — very cost-effective and scalable, but more DIY and less polished.
• Mailgun — solid API and tools, good for dev teams.

SMS

• Twilio — the most common choice, strong global coverage, reliable APIs, easy to start.
• MessageBird — good international coverage and omnichannel options.
• Vonage — also solid for global SMS.
• Plivo — often cost-competitive with decent coverage.

If you want a simple recommendation

• Email: Postmark
• SMS: Twilio

That combination is popular because:

• Postmark is optimized specifically for transactional email deliverability.
• Twilio has the most mature SMS infrastructure and documentation.

If cost is the main concern

• Email: Amazon SES
• SMS: Twilio or Plivo, depending on destination countries and pricing

If you want one vendor for both

• Twilio can do both email and SMS via its ecosystem, but many teams still prefer a dedicated email provider like Postmark or SES for better email performance/cost.

What to consider before choosing

1. Deliverability — especially for password resets and verification codes.
2. Global coverage — SMS rules vary a lot by country.
3. Compliance — opt-in/opt-out, sender registration, 10DLC in the US, etc.
4. API quality and webhooks — for bounce, delivery, and failure tracking.
5. Pricing — SMS costs can vary massively by country.
6. Support — important if messages are mission-critical.

If you want, I can also give you:

• a best choice by startup size
• a cost comparison
• or a recommended stack for your country/region