api-key

Brevo

Brevo (formerly Sendinblue) is a transactional email API. NimblyMail talks to it over HTTPS - no SMTP ports involved.

ZeptoMail

Zoho's transactional email service, with regional API endpoints for data residency or latency reasons.

Resend

A transactional email API built for developers: add a domain, generate an API key, and paste it into NimblyMail.

SendLayer

A dedicated transactional email service over HTTP API: add a domain, verify it, copy your API key.