Preview
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.txt
Refer to the SMTP reference for authentication details, response codes, and language-specific examples.
Read the original announcement