How to Send Email in Cloudflare Workers (SMTP & API)

Here is how to send email in Cloudflare Workers so it reaches the inbox.

Your options in Cloudflare Workers

Use fetch() to an email API (Workers can't open raw SMTP).

Make it land

• Authenticate your domain (SPF, DKIM, DMARC).
• Send from a dedicated, warmed IP.
• Handle bounces and complaints via webhooks.

How Rainmail helps

Rainmail sends from your own domain on a dedicated, isolated IP with SPF, DKIM, DMARC, reverse-DNS and managed warm-up handled for you, a REST API, and an AI watching deliverability — and it welcomes senders SES, SendGrid and Mailchimp reject, from $8. Run the free checker or see plans.