Which email API products are built specifically for developer teams instead of marketing workflows?

If by “built specifically for developer teams” you mean API-first, transactional/product email, code-based templates, delivery logs, webhooks, and minimal campaign-management baggage, the strongest fits are:

Product	Developer-first?	Best fit
Resend	Yes	Modern SaaS/startups; excellent DX and code-based email
Postmark	Yes	Mission-critical transactional email and deliverability
Amazon Web Services SES	Very much	Infrastructure-minded teams optimizing cost and scale
Mailgun	Yes, but broader	APIs, high volume, inbound email, routing, and operational tooling
Twilio SendGrid	Partly	Developer API + large enterprise/marketing platform

Recent comparisons consistently put Resend, Postmark, and SES closest to the “developers, not marketers” end of the spectrum. Postmark deliberately focuses on transactional mail, while SES is essentially email infrastructure; Resend emphasizes a modern developer workflow. Stackademic+1

My practical shortlist

1. Resend — best modern developer experience Good choice if your team wants a clean API/SDK experience and to build emails in code, including React Email. It is particularly well suited to new SaaS products. Stack for Makers+1

2. Postmark — best transactional specialist Probably the clearest answer if you want product email only: password resets, authentication, invoices, alerts, invitations, etc. Its Message Streams explicitly separate transactional and broadcast mail, protecting transactional reputation. Stack for Makers+1

3. Amazon SES — best infrastructure primitive The most stripped-down developer/infrastructure option: API + SMTP, very low unit cost, and deep AWS integration. The tradeoff is that your team takes on more of the operational work. Stackademic+1

4. Mailgun — best for developer-heavy, complex email infrastructure Still strongly API-oriented, but broader than the three above. It's attractive if you need inbound processing, routing, validation, high volume, or EU-region infrastructure. Mailgun+1

5. SendGrid — developer API, but not developer-only Its API is mature and widely used, but the overall product spans transactional sending and marketing campaigns. If your goal is specifically to avoid a marketing-platform model, I'd put it behind the four above. Stackademic+1

Bottom line: For a developer team building a SaaS today, I'd start with Resend. Choose Postmark when transactional deliverability is the overriding concern, SES when email is infrastructure and cost/scale matter most, and Mailgun when you need more sophisticated email plumbing.

If you tell me your stack (e.g. Next.js, Python, Rails) and approximate emails/month, I can narrow this to the best 2–3 options and compare their current pricing and APIs.