SMTP relay without authentication

[marksmenit]

Is it possible to disable authentication for custom SMTP relay? The one we used authenticates based on IP address and sender domain, but not username and password.

[dreambladeflag]

Can you tell me more detail? And can you show me how do your SMTP authentication working?

[marksmenit]

It's a secure email gateway. All it looks at is the source IP address where the email is coming from and the sender domain. It doesn't require any authentication. I tried entering dummy credentials, but the test failed with 503. Currently, entering a username and a password for the relay is mandatory.

[dreambladeflag]

Are you currently using an authentication-free method to connect to SMTP service? Is this still integrated on your platform? I'd like to understand what tools/methods you're using to connect to SMTP for email sending.

[marksmenit]

I am not sure how else to describe it other than how I did twice already.
Here is the documentation of the platform.
https://docs.sophos.com/central/customer/help/en-us/ManageYourProducts/EmailSecurity/index.html

Office 365 also allows relaying emails without a username and password (though with limitations). We also have an internal SMTP relay that also doesn't need authentication. I think, sending emails without a username and password is not that exotic/rare.

I also think my original question is rather clear - Is it possible to disable the user authentication for the SMTP relay, which currently is mandatory?

[dreambladeflag]

BillionMail currently does not allow connections to your SMTP service without a valid username and password. Thank you for your patience. Actually, this is unusual for me because I’m not used to this setup, so I just needed to confirm.

[marksmenit]

We have many clients who have an internal relay that doesn't need authentication.

Any plans to remove this requirement? Needing credentials for SMTP relay.
With this, we cannot integrate the system with the others we already have in place and I'm keen to avoid one-off/different setups.

[dreambladeflag]

Can you provide a server for us to confirm & fix this issue? This would be very helpful for us.

We are patiently waiting for your email at support@billionmail.com.

[marksmenit]

We don't have any Internet-facing servers that are open to public.

All we need is that the username and password fields are not mandatory and when not used, the SMTP authentication is skipped.

[dreambladeflag]

BillionMail's SMTP relay is based on Postfix and appears unable to bypass authentication for relaying.