To open one or more documents as Read Only, select the document(s) and click Read. This can be used for Emails and/or documents.
It allows you to open the emails and/or documents for read only without locking them from other users for edit access. They open in separate tabs in your browser. This allows you to tab through the open emails/documents.
Each document opens in a separate tab in the browser.
You can also use the Preview function to see a quick snapshot of the contents of a document in FYI in the same browser tab. Refer to Previewing a Document.