We are sorry for the late response, I can see that you have previously contacted our team regarding the issue, and a ticket was opened but it's unclear if the issue was resolved. Could you please confirm if the error is still persisting? We have checked your settings and they appear to be correct, but our engineering team was unable to reproduce the bug.
If you're still seeing an error with your outgoing emails please contact our team via live chat or by email at info@dynadot.com and our team would be happy to take another look into this.