If you are eager for a solution and can’t wait for an official update, consider reverting to version 2405 of classic Outlook. However, be aware that doing so means sacrificing several important security fixes.
In an original article published on April 16, 2025, it was reported that users of Microsoft’s classic Outlook app have experienced unusual behavior from their computer hardware while using the application, particularly during email composition. Many have noted a significant increase in processor usage—by 30 to 50 percent—when typing emails, which consequently leads to higher power consumption.
While it’s suggested that this might be a bug, the underlying cause has not yet been determined. Microsoft has acknowledged the issue but has not provided a direct fix.
The problem seems to specifically affect versions of classic Outlook found in the Current Channel, Monthly Enterprise Channel, and Insider channels for users who have updated to Version 2406 Build 17726.20126 or later. For those facing considerable disruptions due to this glitch, a potential workaround is to switch the classic Outlook app to the Semi Annual Channel.
This change could alleviate some of the performance issues until a comprehensive solution is provided. Article information credits its origins to a sister publication, translated and localized from Swedish for broader accessibility.
Users are encouraged to consider their options carefully before deciding to revert to an earlier version of the app.