HubSpot’s Outlook inbox and calendar connections are operational again after a Microsoft 365 outage. The company marked its incident resolved on November 13, 2026.
Partial disruption affected three regions
HubSpot’s incident notice described partial unavailability in North America, Europe and Asia Pacific and classified the disruption under Sales Tools. Its first update was posted on November 12.
The company began monitoring restored services at 10:06 a.m. EST on November 13 and marked the incident resolved at 1:19 p.m. EST.
Microsoft points to a network upgrade issue
Microsoft said on November 14 that it had addressed the underlying issue and restored service to the remaining affected customers and regions, according to a company statement reported by The Associated Press.
In its November 13 explanation, Microsoft said an issue introduced during an earlier network capacity upgrade surfaced following a recent network change. The company said it restored services gradually to validate stability at each stage and promised a full post-incident report once its review was complete.
Connected sales workflows rely on Microsoft access
HubSpot’s technical documentation says its Office 365 inbox and calendar integration uses the Microsoft Graph API. The integration therefore depends on Microsoft services for those connected functions.
According to HubSpot’s connected-email requirements, sending emails from CRM records, logging replies, sequences and scheduled sending require a connected inbox. These capabilities depend on the connection, rather than only on access to HubSpot itself.
Calendar access has a separate role in scheduling. HubSpot says a connected calendar is required for a meeting link to show availability and accept online or automatic bookings. Viewing, editing or creating scheduling pages does not require that connection.
These requirements describe the product’s dependencies, not a confirmed list of failures during the outage. HubSpot’s notice did not quantify affected customers or identify which individual workflows failed.
I can suggest related Tech Help Canada articles based on the topic you’re reading now.
Tech Help Canada Staff researches, writes, and reviews practical content for business owners and professionals. Our coverage spans business, marketing, SEO, technology, and the tools and systems people use to grow and operate online. We focus on clear, useful information backed by research, hands-on experience, and editorial review. Learn more about our team and editorial standards. Need help with something? Contact Us
