Claude Sonnet is the strongest fit for this task because it excels at reading and understanding varied text, applying consistent classification logic, and drafting polished, context-aware replies in one session. You can paste batches of emails and ask it to sort them by type (action required, FYI, newsletter, etc.), rank them by urgency, and produce draft responses for the ones that need replies. ChatGPT is a solid alternative if you already have a Plus subscription and prefer OpenAI's interface for iterative back-and-forth editing. Claude Haiku works well if you want faster, lower-cost processing for high-volume inbox triage where reply quality is less critical. Gemini Pro is worth considering if your email lives in Google Workspace and you want native Gmail integration through the Gemini sidebar.