Right-click on your Inbox folder icon (or wherever you want to have your AR15 folder)
Select New Folder.
Name new folder ARFKOM Mail, or whatever you want.
Click OK.
Now go up to you menu bar, select tools, follow the drop-down menu to Message Rules, and select Mail.
Click on the New button, under "Select the Conditions for your rule", select "Where the message is from the specified account", in the next box you check the box where it says "Move it to the specified folder". Down one box, to the third and last one, marked with "Rule Description", click on the words underlined in blue, and select the e-mail account in question (another drop-down menu) and the folder where you want the mail to be.