Using Rules in Mac Mail to Automatically Delete Old Messages

Before you create the rule you need to decide where you want to move your messages that are older than a year, but less than two years old. I created a folder called “1 Year”, but you can use any of your current folders.
(Right click on the Inbox and click on New Inbox… to create a new folder)
First, open up Mail and select Preferences

Then go to the right most tab called Rules.
Click on Add Rule.

You can now modify the settings of your new rule. I named mine “1 Year Old” and adjusted the parameters as follows:
1) Change “If any” to “If all”
2) Date Received is greater than 365 days old
3) Date Received is less than 730 days old
4) Then, Move message to (select the folder you want to move 1 year old
messages to, I’m using a folder called “1 Year” here)
After you click ok, a window will pop up asking you if you want to apply the rule,
click apply.

Now you need to create a rule for messages older than two years. Click Add Rule again. You only need one conditional to move the old messages to the trash. You should configure yours to how mine is below: