When we try to deliver a message this error pops up:
SMTP: Invalid response code received from server (code: 451, response: Temporary local problem - please try later)
We did totally reset the configurations of Exim and we add the websites to /etc/remotedomains for both web servers and still nothing.
Finally for the solution we have to make sure that the e-mail routing settings for the domain is correct.
In the WebHost Administrator, just click Main >> DNS Features >> Modify DNS Zone and choose the domain you want to modify. At the bottom of the page you will find a setting labeled “Email Routing for”. Automatically Detect Configuration is the default, but you need to select Local Mail Exchanger.