Issue Type: User Experience (UX) / Functional Limitation
Summary: When Inbox Categories (Primary, Deals, Social, Newsletters) are active, Yahoo Mail lacks a mechanism for users to manually train or reclassify senders across tabs. Users cannot promote a secondary/general email to "Primary", nor can they reclassify a "Primary" email back out to general inbox view for future incoming messages. Standard user interactions—such as drag-and-drop, context menus, and rule filtering—either fail silently or offer no destination targets for Category tabs.Steps to Reproduce:Enable Inbox Categories in Yahoo Mail settings.Attempt Move to Primary: Try dragging or moving an email from a secondary tab (Deals, Social, etc.) to the Primary tab. Observe that no "Primary" destination exists in the Move menu, and dragging to the tab header leaves the email where it is without prompting to save the rule for future mail.Attempt Move Out of Primary: Try moving an email currently categorized as Primary back to the general/non-primary view. Observe that there is no native option or menu command to mark a sender as "Not Primary."Attempt Filter Creation: Go to Settings $\rightarrow$ More Settings $\rightarrow$ Filters to force a sender into or out of Primary. Observe that the Choose a destination folder menu only accepts custom/system folders, not Category views like "Primary."Current Behavior:The sorting algorithm is entirely automatic and backend-driven, offering no two-way user override or explicit feedback loop.Drag-and-drop actions between Category tabs are unsupported or fail silently.Filters cannot target or exclude Category views (Primary, Deals, Social, Newsletters).Expected Behavior / Proposed Solution:Two-Way Drag-and-Drop Training:Dragging a non-primary email into Primary prompts: "Move future emails from this sender to Primary?"Dragging a Primary email to another tab (or dropping it outside Primary) prompts: "Remove future emails from this sender from Primary?"Context Menu Actions: Right-clicking any message in the inbox list should include explicit toggle options:Mark as Primary (Always apply to this sender)Remove from Primary (Always apply to this sender)Filter Destination Integration: Include Primary as a selectable target folder within automated Filter rules (both for inclusion and explicit exclusion).Impact:Inbox Categories are a valuable productivity tool, but without two-way manual overrides, users lose control of their message organization. When important mail stays hidden in secondary tabs, or non-essential mail clutters the Primary tab, users are forced to abandon the feature entirely.