Apple's Mail app recently introduced inbox categories in iOS 18, automatically sorting messages into Primary, Transactions, Updates, and Promotions. While the feature aims to help users manage email overload, many found the automatic sorting inconsistent, with important senders sometimes landing in the wrong folders.

A hidden feature allows users to manually categorize senders by swiping left on any message, tapping 'More,' and selecting 'Categorize Sender.' This option lets you choose which folder future messages from that contact will appear in, giving users control over the automated system. The feature addresses a common frustration where frequently contacted senders don't appear in Primary despite regular communication.

For users who rely on Apple's Mail app across iPhone, iPad, and Mac, this manual categorization option transforms the inbox categories from a potentially frustrating feature into a genuinely useful tool. Without this hidden capability, many users might disable the automatic categorization entirely. The ability to override Apple's sorting decisions ensures important communications never get lost in secondary folders, making the Mail app's new organizational system far more practical for everyday use.