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

If you mean email APIs built for product/engineering teams—things like transactional emails, app notifications, templates, webhooks, deliverability, and code-first workflows—these are the main ones:

Developer-focused email API products

• SendGrid – strong general-purpose email API for transactional and bulk sending; popular with developers.
• Mailgun – API-first email sending, routing, validation, and logs; very developer-centric.
• Postmark – focused on fast, reliable transactional email with excellent developer experience.
• Amazon SES – low-cost, scalable email sending via AWS; very infrastructure/developer oriented.
• SparkPost – email API and analytics built for high-volume sending and deliverability.
• Resend – modern API built specifically for developers and product teams, especially for transactional/product emails.
• Mailjet – offers APIs, but is often used for both dev and marketing; less purely developer-only than the ones above.
• Brevo (Sendinblue) – has APIs, but it’s more of an all-in-one marketing platform than dev-first.

More explicitly “developer-team” oriented

If your goal is not marketing automation, but rather:

• password resets
• receipts
• notifications
• account emails
• system alerts
• app-generated messaging

then the most developer-centric options are usually:

1. Postmark
2. Mailgun
3. Resend
4. Amazon SES
5. SendGrid (especially if you want a mature ecosystem)

What to look for

Developer-team email APIs usually emphasize:

• simple REST API
• SDKs for common languages
• webhooks for delivery/bounce/open events
• template management via code
• suppression lists and domain authentication
• high deliverability
• logs and observability

If you want, I can also give you:

• a comparison table of these products,
• the best choice for startups vs enterprise, or
• a list of products that are explicitly marketing-first and should be avoided for dev teams.