If you have received email notifications that look slightly different to your current email notifications, that is because you were yet to activate your account with us.
If you see the following: *USERNAME* ADDED A FILE FOR YOU,*USERNAME* WANTS YOU TO JOIN A CONVERSATION, or *USERNAME* LEFT A COMMENT FOR YOU, your account is not activated. You will also find that any subscribed emails that would normally have a 'previous comments' section displayed will instead show the 'Get Started' block (that is displayed in activation emails).
The reason we send you slightly different notifications is to give you a friendly reminder that your account is currently unactivated, although you can still interact with the application via email if you wish to. However, you will not get the full benefits of having an active account (such as being able to download and upload files) until you are fully activated.
So how do you activate your account? It's easy - either select the Get Started option in your activation email, or Join The Conversation on a subscribed email notification, and you will be asked to create a password. Once you have done this, you can now login and enjoy the full experience of the application without having to console yourself with 'email only' correspondence - and why would you?