What is the "Check External Email" link used for?
If you have set up existing email accounts to be cleaned, Mailshell normally checks for new messages at those accounts every fifteen minutes automatically. If you are expecting a message and would like to check manually, though, you can do so by clicking this link.
What does "set as my Mailshell start page" mean?
If you want to go to this page immediately after signing in, click this link at the bottom of the page. You can choose to start in the Spam Filtering Overview or Disposable Email Addresses sections of Spam Filtering or in the Inbox or Folders sections of Check Mail. (Note that you can also choose your start page by using the menu in Display Options.)