Problem
You have left a message in a squirrel mail account in dreamhost for a long time and it gets archived by dreamhost. According to the dreamhost you should be able to get to your archived messages, by looking at the old-messages folder.
The problem is that just by logging in to squirrel mail the folder doesn’t get displayed on the left hand side.

Solution
Log on to squirrel mail and go to ‘Folders’ menu at the top.
In the ‘Create Folder’ put ‘test’ or anything that you would like in the text box, and make sure that in the dropdown box you select ‘INBOX.old-messages’, so your newly created folder is a subfolder of the ‘inbox/old-messages’ folder.
Create the subfolder, refresh the page, and in your left hand the old-messages folder should appear.