Click on the Advanced tab and match the same settings as shown in the below screenshot. You should now be back in the Account Preferences window.You can find the settings to use with each of your mail accounts with SiteGround with your Mac Mail in your Site. Change the desired settings and click the Save button to apply them. Click the Accounts tab, select your email from the accounts list and click the Server Settings tab. This can take some time depending on your connection speed. Open the Mac Mail application and go to Mail -> Preferences. Enter the Outgoing Mail Server settings in the designated fields as shown below. Be sure to place a check mark next to Use authentication when sending mail and click Continue. After you click Continue, it will test the connection to the server and test the user name and password. 'To do so, just enable the SSL options in your email client application using the port assignments of 993 for IMAP accounts, 995 for POP accounts, and 25 for accounts using as the outgoing mail server.' and 'Because not all email client applications support SSL in the same way, if you experience any difficulty with these settings.This can take some time depending on your connection speed. Enter the Incoming Mail Server settings in the designated fields as shown below and click Continue. After you click Continue, it will test the connection to the server and test the user name and password.
Type in your name, email address, and password and click Continue.On here, click on the + button at the bottom left. Click the Accounts icon in the Mail Preferences window.If you have not yet set up any accounts, the Mail Setup window will appear, and you can skip to Step 4. Click the Mail tab from the top menu and select Preferences.Open Mail by clicking on the Mail icon.Follow the below steps to set up your Windstream email account in Mail in macOS High Sierra: