Update as of April 25, 2025: Microsoft confirmed the issue and has already implemented a fix. However, the update won’t be available until "early May" for the Beta Channel, "mid-May" for the Current Channel Preview, and "late May" for the Current Channel. If waiting isn’t an option, users can revert to version 2405 of classic Outlook, though this means sacrificing several important security updates.
Original story from April 16, 2025: If you’re still using Microsoft’s classic Outlook app for emails, you may have noticed unusual behavior in your computer's hardware—especially when typing.
Earlier this week, Microsoft issued a warning acknowledging that the classic Outlook app can significantly increase CPU usage. When composing an email, processor activity may surge by 30 to 50 percent, leading to higher power consumption. While this appears to be a bug, its exact cause remains unknown.
Currently, there’s no direct fix for the issue, but Microsoft notes that it only affects certain versions of classic Outlook running on the Current Channel, Monthly Enterprise Channel, and Insider channels, following an update to Version 2406 Build 17726.20126 or later.
