Apple today provided developers with a second release candidate version of an upcoming macOS Sequoia 15.4 update for testing purposes. The new RC is available a few days after Apple released the initial RC earlier this week.
Registered developers can opt-in to the macOS Sequoia beta through the Software Update section of the System Settings app. An Apple ID associated with an Apple Developer account is required to get the beta.
macOS Sequoia 15.4 brings Mail Categorization to the Mac for the first time, reorganizing the Mail app into dedicated categories like transactions, updates, promotions, and primary, a category that surfaces the most important emails first. The update brings a range of new emoji characters to the Mac.
Read more at MacRumors.com