MailCode

I kept hitting the same wall: ten years of mail, an Exchange server with a quota, and a stack of PST files nothing on my Mac would open. The usual advice is to delete things. I wanted the opposite  keep all of it, on my own disk, and find any of it.

 So I built MailCode.

 Mail lives on your disk, not in someone's cloud. Exchange, Microsoft 365 and IMAP in one window, every message archived locally. No service of mine in the middle. When the server quota fills up you move messages onto local or external storage, and it fetches the attachment bytes before anything is removed from the server.

 It opens the archives nothing else will. PST and OST, .eml, .msg, maildir folder tree intact, everything indexed on the way in.

 Search is a query language, not a box.f: s: b: to: cc: in: df:/dt: label: flag:, combined with AND or OR. Ask "find phone number of Alice Chen" in plain words and it reads the answer out of the mail it found — local pattern work, no model involved.

 A message is usually a task. Seven flags, six of them mapped onto an Important/Urgent matrix. Due dates, reminders, notes that stand on their own, and the whole set readable as a Gantt style timeline. None of it moves a message.

 Numbers from my own archive rather than a demo one: 280,901 messages, 31 GB,1,208,950 attachments. Median search 5 ms warm.

 On the Mac App Store now, macOS 12+, Apple silicon. Free 14-day trial, then a one-time purchase, no subscription. Windows is built and waiting on installer code signing.

 Two things I'd like input on:

 1. The category is crowded and mostly subscription. Is "one-time purchase, your mail stays on your disk" a real wedge, or am I just the cheap option?

2. The people who need this have enormous Exchange mailboxes, sysadmins, lawyers, consultants. Beyond the App Store listing, where would you look?

 Electron, better-sqlite3, FTS5, and a lot of fighting with EWS. Happy to go into any of it.

Every app in my category now has an AI subscription attached. I built the same features compose, summarise, refine, translate and then took the resale out.

 On the Mac App Store build there is no server of mine in the path. You paste in your own OpenAI or Anthropic key and the app talks to the provider directly. I don't meter it, mark it up, or see the text.

The reason is that the pitch of the whole product is that your mail stays on your disk and nothing routes through a machine I run. A relay would have made that false in the one place the content is most sensitive  the body of themessage. I'd have needed a paragraph in the privacy policy explaining the exception, and that paragraph is the product arguing with itself.

 What I keep hearing is that this leaves money on the table usage-based AI is where the margin is. Maybe. But the buyers I have are the ones with a compliance officer, and "no third party in the path" closes them faster than a feature does.

The part I'm actually proud of isn't AI at all. Translating an attachment properly means translating the file, not the preview. The viewer already renders .docx through mammoth and .xlsx through SheetJS, and translating that HTML would have been an afternoon's work — but then the download would be a different document: no styles, no headers, no page setup. So it rewrites the file. A .docx is XML in a zip; the entries it doesn't touch get copied across still compressed, and the two or three it does rewrite go through the platform's own CompressionStream. No zip library, works offline, works inside the App Store sandbox. Preview and download are the same bytes, and "Show Original" is a re-render of the untouched ones. PDFs keep their page and wear the translation over it; scanned ones go through macOS's own OCR.

Has anyone else taken the resale out and regretted it? If you're charging for AI on top of a one-time purchase, is it actually converting?