1/ Go to Mail > Preferences
2/ Click on the Accounts tab at the top of the pop-up box
3/ Click on the “ + “ button on the lower left corner to add a new account.
4/ Add your Name, the email address you want to add and it’s password to this form.
5/ After you click Connect you’ll see the Incoming Mail setup form. Make sure the Account type is set to IMAP. In the Description field just add something descriptive or leave it blank and Mac Mail will auto-fill it. Add the Incoming Mail Server link credentials. Then click the “Continue” button.
6/ The next screen will be to set the Outgoing Mail Server. Use the credentials provided by your host. Make sure you click the “Use Authentication” box. Then click the “Continue” button and your email client will attempt to connect with your new email account.
7/ If all is successful you will be shown the account summary screen, which displays your settings and asks you if you want to bring the account online. Just click the “Create” button and your new account will be available to you.