Email Service - 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:

<div><div><span>curl</span><span> </span><span>--ssl-reqd</span><span> </span><span>\</span></div></div><div><div><span>  </span><span>--url</span><span> </span><span>"smtps://smtp.mx.cloudflare.net:465"</span><span> </span><span>\</span></div></div><div><div><span>  </span><span>--user</span><span> </span><span>"api_token:<API_TOKEN>"</span><span> </span><span>\</span></div></div><div><div><span>  </span><span>--mail-from</span><span> </span><span>"welcome@yourdomain.com"</span><span> </span><span>\</span></div></div><div><div><span>  </span><span>--mail-rcpt</span><span> </span><span>"user@example.com"</span><span> </span><span>\</span></div></div><div><div><span>  </span><span>--upload-file</span><span> </span><span>mail.txt</span></div></div>

Refer to the SMTP reference for authentication details, response codes, and language-specific examples.