Recently I’ve configured a client’s hosting to point its MX to an external Spam Filter. After pointing to the new MX server, I started receiving the following errors:-
lowest numbered MX record points to local host
Please turn on SMTP Authentication in your mail client.
After research, it seems that I’ve configured the Cpanel Email Routing wrongly.
- Email Routing needs to be set to Local instead of Remote even though the MX IP is not local to the server.
- The domain name needs to be set inside the file /etc/localdomains. (By right once you set Email Routing to Local, the domain name should be automatically inserted into the file. In my case, it did not. I’ve to manually insert it in.)