In this area you will find two distinct type of messages. Your account's alarms which will have all the warnings generated by your apps or account limits and the inbox messages (which might also contain alarms) which you'll receive if you enable browser notifications.
To access this area, click in the Your Messages button in your account's menu:
In this area you will see the two options which can be access via the tabbed menu:
Clicking in the alarms tab will take you to the list of warnings (only if you've checked the checkbox Email Warnings as described in the Your Account page):
This list will contain all several types of warnings, from due to expire or expired certificates to account limits warnings, it's a always a good idea to pay this page a visit so you can rest assure things are running smoothly.