API archive entry · source-reported
SMTPfast
Send transactional email, manage contacts and broadcasts, free 3,000 emails/month
Other Email APIs
These records share a directory category and are ordered by similarity of reported access facts. They are a shortlist, not proof of drop-in compatibility.
mailfloss
Stop spam signups: block disposable and invalid emails and suggest typo fixes. 500 free a month
API key · HTTPS reported · CORS Yes
ContactLint
Validate email syntax, MX, disposable and role addresses with typo suggestions, plus phone numbers
API key · HTTPS reported · CORS Yes
Mailfornet
Disposable inboxes for end-to-end signup tests, with long-polling and HMAC-signed webhooks
API key · HTTPS reported · CORS Yes
Cloudmersive Validate
Validate email addresses, phone numbers, VAT numbers and domain names
API key · HTTPS reported · CORS Yes
Email Validation
Validate email addresses for deliverability and spam
API key · HTTPS reported · CORS Yes
EmailJS
Send emails directly from client-side JavaScript without a backend server
API key · HTTPS reported · CORS Yes
How to compare them
Coverage
Compare exact endpoints, fields, geography, history, and update frequency.
Operating cost
Model request volume, caching, overages, support, and migration cost.
Integration risk
Test auth, errors, pagination, latency, versioning, and outage behavior.
Data rights
Review attribution, redistribution, retention, privacy, and commercial-use terms.
Source reference
This page separates source-reported facts from questions that need live provider verification.