There are a couple of ways to do this. However, let’s do it the simplest and easiest way. Firstly, you will need to ensure that you have created the mail account you wish to use. In this case we will use; firstname.lastname@example.org.What mail servers should I use?
You will need to use the mail server for primary domain. For example, if you’re primary domain is yourdomain.com and you just added example-domain.com you would use yourdomain.com for your settings in your mail client. Please see the example below:
You want to access email from email@example.com (new domain you just added) and you want to:
Server Name: mail.yourdomain.com
Using the above configuration, you will be able to receive your email from the add-on domain that you have recently added just like you would from your primary domain.