Rules in Apple Mail are filters that you can use to sort incoming mail into folders.
1 Go to Mail... then click Preferences.
2 Select Rules... then click Add Rule.
3 Enter a description.
4 Choose to sort if any or all the following conditions are met.
5 Select a condition. This condition will sort any mail that contains the word "Test".
6 Click plus to add another condition... and set the action to be taken when the conditions are met.
7 Now when the condition is met, the message will be moved to the Support mailbox. Click OK.
8 Click Apply to apply the rule to messages in your mailbox.
That's it! Now you know how to create rules in Apple Mail.