Signing In
If you have not started using the Mail app, this is a great time to start. Go to your Applications folder and double click on the icon for your Mail app. Enter your user name and password. Then click on the Create button.
For the first time, it will take a while for it to load your mailbox and fetch the mails from the server.
Creating A Rule
To make your rule, simply click on Mail -> Preferences.
Click on the rules tab, follow by Add Rule.
Now you can name your rule. Select ALL from the first row of dropdown field. In the second row, select “FROM”, “IS EQUAL TO” from the first two dropdown fields and enter the email address that you want to block in the third input field. In the third row under the “Perform the following actions”, select “Mark as Flagged” to flag all the message from this sender.
Additionally, you can also get it to highlight the message by selecting the color from the “Set Color” field.
Lastly, click OK. You should see your new created filter system implemented in your inbox.
Now you can enjoy all of the sorting that you need to do with your inbox. Yes, you will need to make a new rule for each address you want to highlight or flag. On the bright side, it allows you to micro-manage and organize your incoming emails, so that is not a bad thing too. Do also check out how to backup your Gmail using mail rules in Mac.