Further, within your PayPal account preferences, you can subscribe to email notifications about system problems and scheduled maintenance activities.

Here is a sample email which was sent today:
mtsoncall Jan 08 2007

The PayPal APIs were intermittently unavailable between 01-08-2007 08:08 PT and 01-08-2007 10:00 PT

During this time API calls intermittently failed with a 500 error.

This issue has been resolved.

We apologize for any impact caused by this incident.

Sincerely,
PayPal Merchant Technical Support Team