Postmark

SMTPfast is a simple email API for developers with a free tier that includes 3,000 emails/month, 1 domain, and 1,000 contacts, with no credit card required.

Detect and block disposable email addresses. Free plan of 250 lookups a month and no card required.

Block disposable emails, catch typos, and validate MX records via a simple API. 100 free requests/month.

AI-First Transactional & Marketing Email Service. Free tier: 5,000 emails/mo, 200 emails/day, 10,000 contacts, 5 domains. No credit card required. SDKs, MCP and REST API available.

Free SMTP relay on the msgwing.com domain, up to 200 emails/day, no paid tier. Sends from a shared @msgwing.com address only (no custom domain). Ready-to-run code examples in 15 languages plus Windows Server/Linux/network printer setup guides. ⬆️ Back to Top

email automation workflows, 5k tracked events and unlimited contacts free.

Waitlist management software for product launches. Create branded waitlist pages, collect and verify email subscribers, manage signups with tags and analytics. Free plan includes 100 subscribers/month, 1 waitlist, and API access.

Bulk and API email verification service. 100 free verifications/month