We investigated several of the reports and identified these are not due to a system issue. For example, in one case the customer deleted the user that owned their API keys causing API calls to be unauthorized.
Please submit a detailed support ticket if you have any issues.
Posted Dec 14, 2017 - 08:57 EST
Update
We are continuing to investigate reports from a few customers, though we are not seeing a widespread issue.
Posted Dec 14, 2017 - 08:07 EST
Investigating
We are experiencing an elevated level of API "unauthorized" errors for our APIs for some SparkPost and SparkPost Enterprise customers (including Transmissions API and SMTP injection API).
Note: This issue does not impact our SparkPost Enterprise customers hosted in the EU.
Posted Dec 14, 2017 - 07:37 EST
This incident affected: Metrics API (Metrics API - USA), Transmissions API (Transmissions API - USA), Events API (Events API - USA), SMTP API (SMTP API - USA), Sending Domains API (Sending Domains API - USA), SMTP Delivery (Outbound Message Delivery) (SMTP Delivery - USA), and Relay Webhooks Delivery Service (Relay Webhooks - USA).