Microsoft Teams to Enforce Messaging Safety Defaults Starting January 2026

Microsoft will automatically enable three Teams Messaging Safety protections (weaponizable file type protection, malicious URL protection, and a "report incorrect security detections" feedback mechanism) for tenants still using default settings starting January 12, 2026. Tenants that have previously customized and saved messaging safety settings will not be affected; administrators should review and, if desired, adjust settings at Teams admin center > Messaging > Messaging settings > Messaging safety before the deadline to avoid user disruptions from blocked file types or URL warnings.