dkimvalidator.com

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

Free API for temporary email testing, free public email hosting, outbound capture, email-to-slack/websocket/webhook (1,500 monthly API limit)

6,000 emails/month free (200 emails daily sending limit)

SMTP relay and email API for developers. 5,000 emails per month, unlimited domains, free email verification, blacklist monitoring, mail tester and more.

Ethereal is a fake SMTP service, mainly aimed at Nodemailer and EmailEngine users (but not limited to). It's an entirely free anti-transactional email service where messages never get delivered.

Free email infrastructure grader that checks SPF, DKIM, DMARC and mail server configuration. Scores any domain out of 100. No signup required.

transactional and broadcast email API. 3,000 emails/month free, then as low as 8¢ per 1k

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.