Office 365 offers 99.9 percent uptime, guaranteed by a financially-backed SLA. However, the remedial Service Credit guaranteed in the SLA is subject to accurate reporting of downtime. Any downtime that goes unnoticed or isn't reported before being resolved won't count against the SLA. What's more, detecting and reporting on service outages using the Office 365 admin center is difficult.
Microsoft only provides service outage notices in the Office 365 service health dashboard. If you don’t constantly check this dashboard, you might not report downtime quite as quickly. O365 Manager Plus overcomes this limitation of the Office 365 admin center by sending out immediate email notifications whenever a service declines. These automatic alerts enable you to report downtime events as soon as they occur.