Re:Microsoft Outlook/365 still down after 12 hours
by sugarkjube on Friday November 13, 2026 @05:00AM
(#50481010)
> Uptime Percentage : Service Credit
> < 99.9% : 25%
> < 99% : 50%
> < 95% : 100%
These targets feel very very low nowadays.
99% uptime for email means 3.5 days/ year no email.
(although 99.9 = about 8 hours/year would seem bearable - but maybe not for a company like microsoft)
Re:Microsoft Outlook/365 still down after 12 hours
by moebrowne on Friday November 13, 2026 @05:54AM
(#50481658)
> 99% uptime for email means 3.5 days/ year no email
Depends on how it appears, if it was one or several large chunks that is much more disruptive than minutes per day. 3.5 days/year is equivalent to less than 15 minutes/day.
It sucks no matter how you slice it, but the severity/impact depends on more than the aggregate downtime.
At my day job, we have a calendar integration that polls Microsoft's Graph API across hundreds of Microsoft 365 tenants. We saw our first metric spike in 5xx errors at 2026/11/12 17:33 UTC. As of writing it's 2026/11/13 09:44 UTC and we are still encountering a full outage, so 16 hours and 11 minutes.
With a SLA calculator [1], assuming no other downtime this month and entering `16h 11m 0s`, we get: * Yearly SLA: 99.82% * Monthly SLA: 97.78%
I found an SLA document list here [2].
I downloaded Service Level Agreement for Microsoft Online Services (WW) English (2026/10/01). There's a heading for Exchange Online that says:
Uptime Percentage : Service Credit < 99.9% : 25% < 99% : 50% < 95% : 100%
Which seems to agree with what the original commenter said for this month.
[1] https://uptime.is/reverse [2] https://www.microsoft.com/licensing/docs/view/Service-Level-...