Authenticated SMTP submission now available in beta
You can now send emails through Cloudflare Email Service using authenticated SMTP submission on smtp.mx.cloudflare.net:465. SMTP joins the REST API and the Workers binding as a third way to send transactional email — useful for existing applications that already speak SMTP and language-native SMTP libraries (Nodemailer, smtplib, PHPMailer, JavaMail).
| Setting | Value |
|---|---|
| Host | smtp.mx.cloudflare.net |
| Port | 465 (implicit TLS) |
| AUTH | PLAIN or LOGIN |
| Username | api_token |
| Password | A Cloudflare API token (account-owned or user-owned) with Email Sending: Edit |
Submissions enter the same delivery pipeline as the REST API and Workers binding: identical limits, automatic DKIM and ARC signing, and shared dashboard logs.
Send your first email with a single command:
curl --ssl-reqd \
--url "smtps://smtp.mx.cloudflare.net:465" \
--user "api_token:<API_TOKEN>" \
--mail-from "welcome@yourdomain.com" \
--mail-rcpt "user@example.com" \
--upload-file mail.txtRefer to the SMTP reference for authentication details, response codes, and language-specific examples.