User impact: Users may be unable to leverage one or more secondary functions within Outlook on the web.

More info: Users encountering this issue may experience impact to one or more of the following features within Outlook on the web:

– Search results and suggestions for Email, Calendar and Contacts
– Content Labeling Policy functionality
– SafeLinks settings
– Outlook add-in settings
– Favorite folder add/remove
– Subscribing to new published calendars
– Suggested email replies and attachments
– Roaming signature management
– Email translation
– Weather feature visibility and management within Outlook calendar
– Viewing and editing To Do items, OneNote items, and activity notifications in the Outlook side pane
– Managing connected accounts
– Viewing meeting insights, related content, and meeting transcripts in calendar events
– Managing Outlook groups
– Viewing “Getting Started” tooltips and “What’s New” feature suggestions
– Viewing and editing Loop components.

As a workaround for the signature issue, signatures can be added to email drafts manually, or be applied through the Outlook desktop client.

We believe impact is specific to tenants configured with both split traffic between Evolved Security Token Service (ESTS) and Outlook on the web or IP enforcement conditional access policies.

Current status: Our ongoing investigation has identified a potential fix which may reduce or eliminate the underlying authentication issue. We’re validating this fix for efficacy to confirm whether it’s viable as a path to remediation.

Scope of impact: Some users may be unable to leverage one or more secondary functions listed in the More info section within Outlook on the web.

Start time: Monday, June 26, 2023, at 7:00 AM UTC

Root cause: A recent deployment, intended to resolve an unrelated issue by modifying the authentication pathway leveraged by the affected functionality, introduced an authentication issue that resulted in impact.

Next update by: Monday, July 24, 2023, at 7:30 PM UTC