Microsoft Advertising states on its own status page that the Microsoft 365 outage on November 12, 2026 may have affected the spending of individual advertisers. According to Microsoft, the advertising platform itself remained undisrupted. The cause lies with Outlook: Ads appear there in the inbox, and where Outlook was unreachable, fewer ad requests came in.
The entry titled „Microsoft Advertising Impact from Microsoft 365 Service Disruption“ gives the start as November 12 at 13:15 Central European Time. The last update is from November 13 at 19:34. The affected area is Ad Delivery, that is, the serving of ads. According to the entry, the end of the disruption is determined by the general Microsoft 365 status page; Microsoft Advertising does not confirm it itself.
According to Microsoft, fewer ad requests came in from Outlook because users could not use Outlook as usual. Fewer requests mean fewer opportunities to serve an ad, and that can reduce the spending of individual customers. Microsoft does not say how many accounts were affected, in which countries, or in which campaigns.
From outage to fewer ads
This is how Microsoft Advertising describes it in the status message of November 13, 2026
- Microsoft 365 disruption on November 12
- Users cannot use Outlook
- Fewer ad requests from Outlook
- Spending of individual advertisers may decrease
Microsoft names neither accounts nor countries nor campaigns
Source: Microsoft Advertising
Which users see the ads is explained by the support page About ads in Outlook: Ads appear there in free personal accounts such as Outlook.com or Hotmail, next to the messages in the inbox and with the label „Ad“. Users with a Microsoft 365 subscription see no advertising in Outlook. The status message refers mainly to Exchange Online. The fact that Microsoft nevertheless mentions effects on spending suggests that free accounts were also affected. Microsoft has not confirmed this.
As advertising networks to which Outlook passes an identifier when displaying ads, the support page names the Microsoft Audience Network and the Meta Audience Network. The campaigns most affected are therefore likely to be those served via the Microsoft Audience Network. This is an inference from the support page; Microsoft has not confirmed it. Whether the outage also affected campaigns via Meta, Microsoft likewise does not say.
How do you check whether your account was affected?
It is best to compare impressions, clicks, and spending from November 12 and 13 with the average of the previous week in the Microsoft Advertising reports, separated by Audience and Search campaigns.
If the values normalize again after the outage, that fits the notice. A decline that persists needs a different explanation, such as changed bids, budgets, or ad approvals.
What this means for you
It is best not to change bids and budgets because of two unusual days. Lower spending on November 12 and 13 says nothing on its own about the quality of your campaign, and Microsoft mentions neither a refund nor compensation in the notice.
If you create reports for clients, it is best to note the incident in the analysis and save the status message along with its date. That way you explain a drop in impressions without the client doubting the campaign.
Microsoft Advertising last updated the status message on November 13, 2026.
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