Inbox Search

Outlook's built-in search works fine when you remember the exact words. But what about that email from a recruiter last spring about a backend role, or the contract attachment your manager sent before the holidays? Inbox Search lets you find emails the way you actually remember them, by meaning rather than just keywords.

Type what you're looking for in plain English. Inbox Search understands intent, synonyms, and related concepts, so "quarterly budget approval" finds the email even if the original message said "Q3 spend sign-off." It combines semantic search with traditional keyword matching, so your results are both relevant and precise.

Your email never leaves your device. Most AI search tools send your messages to cloud servers for processing. Inbox Search doesn't. A small open-source AI model (33MB) runs locally in your browser using WebAssembly and builds a private search index right on your machine. No external servers, no third-party AI services, and no email content transmitted anywhere.

How the search works:

• AI semantic understanding matches meaning, not just words
• Traditional keyword matching (BM25) handles exact terms, names, and IDs
• Reciprocal Rank Fusion blends both methods so you get the strengths of each
• Results are ranked by relevance, with a one-click switch to sort by date

Power-user filters when you need them:

• from: and to: narrow by sender or recipient
• folder: searches within a specific folder
• has:attachments finds emails with files
• Date ranges scope your search by time
• "Exact phrases" in quotes return literal matches
• A minus sign (-) excludes terms

You can mix filters with natural language in a single query. For example, "vendor renewal questions from:legal has:attachments" combines structured filters with semantic meaning at once.

It fits how you already work. Pin Inbox Search to the Outlook sidebar and it stays one click away while you read and reply to email. There's no separate app to open and no context switch. It runs on Outlook for Windows, Outlook on the web, and Outlook for Mac, and it works with Microsoft 365 accounts as well as personal, work, and school Microsoft accounts.

No subscription, no in-app purchases, and no upsells. It needs nothing beyond the Microsoft account you already use.

Who it's for: knowledge workers, consultants, recruiters, salespeople, founders, lawyers, and researchers. Anyone whose inbox holds important history that's hard to dig back out. It suits busy individuals and small teams alike. If you've ever lost ten minutes scrolling through search results and trying different keyword combinations, Inbox Search is built for you.

A few honest notes. The AI model is good but not perfect. Semantic search occasionally misses the mark, which is why keyword matching runs alongside it as a safety net. Initial indexing takes a few minutes depending on mailbox size, and the index updates as new mail arrives. The semantic model currently supports English only. Other languages still work through keyword search, with broader language support planned.

Install Inbox Search to make your inbox properly searchable, without giving up control of your email.