Sending emails with Email Routing Feature

Hi! I think the Email Routing feature of Cloudflare is Really Cool! However adding some features can make this even cooler!

My suggestion is making a domail like this <cloudflaremail.dev> and giving each user an unique subdomain <uid.cloudflaremail.dev>.

Now if you send mail to this email address “[email protected]@uid.cloudflaremail.dev then the mail will be delivered to the destination mail adress via this procedure.

Also if you try to send mails to mailadress.uid.cloudflaremail.dev it would be sent from [email protected]
With this people can use their own personal mail and mailing service and still get the features of a mail server without actually having it.

Yes many might not know but email addresses support quotation mark. This feature can make cloudflares email forwarding unique.

(Also consider giving me the beta access of Email Routing and all beta features quickly if you like this idea. Lol)

I don’t see much reason to give each user a subdomain off a Cloudflare mail domain. You already have a domain here to use.

That’s known as an “Open Relay” and is very bad.

Would you care to elaborate? AFAIK several services in the markets allow these types of behavior, such as SimpleLogin, AnonDaddy. Could you elaborate a bit on why it is bad?

A spammer can fire off a bunch of email using the mailadress.uid.cloudflaremail.dev syntax with the [email protected] return address.

Open Relays, by definition, let anybody spew email without authentication.

1 Like

If I understand correctly, open mail relay seems to be more of a misconfiguration rather than feature? I would argue that with DKIM, SPF properly configured, cloudflare should be able to send email ( without introducing more spamming than there is already )

At best (worst?) this method would not be impacted by DKIM/SPF/DMARC because any email through this forwarder will look the same, regardless of legitimacy.

What if only allowed mails from a single verified address?
If mails dkim & spf is verified it doesn’t seem like a problem to me.