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).

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 "[email protected]" 
  --mail-rcpt "[email protected]" 
  --upload-file mail.txt

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