Exim no valid cert for gatewaying (#5.7.1)

I tried different ip. It seems it is not ip blocking issue. But some domains rejecting mails. I also tried with ssl and non ssl setting in mail client.
Error is:
Diagnostic-Code: smtp; 553 sorry, that domain isn’t in my list of allowed rcpthosts; no valid cert for gatewaying (#5.7.1)

Any idea?

This could be something related to exim?

Mostlikely but have no idea…

Stucked here. :upside_down_face: Can I downgrade exim for a try?

This error message is reported by your email client because the check box labeled “My Server Requires Authentication” is not checked. Your email client attempts to send the email to the server without providing a password, hence the server replies that you are not allowed to relay without proper authentication.

To resolve this issue you will simply need to check the checkbox next to “My Server Requires Authentication” in your email clients settings.

Sounds like a client side problem

Of course it was the first thing I checked. But it is not realted to that. Authentication checkbox is checked. I also get this error from webmail.

I think I found issue for my situation. Remote site has more than one mx records and two of them is not set to recieve mails. So when dns send mail to those mx records, getting above error.
I told them to remove them.

But for test, I want to tell/force exim or dns to use specified mx record. How can I do that?