If you have just opened a new Dreamhost webmail address and wondering where the spam, sent, and old messages folders have gone, then this tutorial is for you.
Navigate to your settings>>Folders and enable the Drafts, Sent, Spam, and Trash just like the image below.
If you are not seeing other folders it means that you will have to contact Dreamhost support.
This is what was happening to me and after checking in with support they were able to fix it.
Hope this quick tutorial helps.