API & InfrastructureJuly 04, 20266 min read
Transactional Sending APIs vs SMTP (SES, Resend, Mailchimp)
Traditional SMTP configurations are often blocked in modern web apps. Explore why HTTPS JSON API routes are the secure, lightweight alternative for developers and marketers.
When connecting your website or app to dispatch automated order receipts and welcome emails, developers choose between traditional SMTP and modern HTTPS APIs.
Why Modern Web Apps Prefer Sending APIs over SMTP
- Port 443 Support: Modern cloud hosting providers often block traditional SMTP network ports (25, 465, 587) to prevent spam abuse. HTTPS APIs communicate over standard Port 443, which is always open.
- Superior Execution Speed: HTTPS API calls execute in milliseconds, while SMTP requires multiple network roundtrips to establish connections.
- Better Security: Transmitting API keys inside encrypted POST JSON payloads prevents credential leakage in server logs.
Emailnya provides built-in proxy connectors for top transactional email providers (including Resend, Brevo, Mailchimp, and AWS SES) allowing you to dispatch test sends instantly.
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