Original Summary

I kept hitting places where email is the only door that is open: a boat on satellite data, a locked-down work laptop that blocks every chat site, an e-ink reader, my parents' tablet. So I built Penpal. You email [ hi+reddit@askpenpal.com ](mailto: hi+reddit@askpenpal.com ) and it replies in the same thread, usually in under a minute. Reply and it remembers the conversation. It can search the web for anything current, read a link you paste, read an email you forward to it ("is this legit?"), and read files you attach: PDFs, Word, Excel, CSV, and photos of letters or bills. Ask a follow-up and the document is still there. No account, no password, nothing to install. Three replies a day are free, then it is $5 for 50. Tech: Go and Postgres on a small box, Resend for inbound and outbound mail, DeepSeek V4 Flash through OpenRouter, Stripe for checkout. Attachments are read in-process rather than shipped off to a service: PDFium compiled to WebAssembly and run in an empty sandbox, plus the Go standard library for docx and .eml. Three things that surprised me building it: - Inbound webhooks do not reliably carry In-Reply-To, so threading uses a plus-address in Reply-To instead of matching headers. - An AI that answers any email will happily argue with an out-of-office reply forever. It drops auto-submitted mail, list mail and failed SPF or DKIM before anything is written down. - I added a cap on how much text you can paste in. The first version sliced by bytes, which cuts a multi-byte character in half, and Postgres then rejects the whole thing. It would have silently dropped every long email that was not in English. What I would like feedback on: whether email-only access actually solves a problem you have, and what breaks when you try it. It is free to try right now, just send it a question.   submitted by   /u/newzinoapp [link]   [comments]

  • 情报分类：商业与市场研究
  • 分类依据：内容涉及商业、投资或市场动态
  • 信息来源：Reddit · SideProject
  • 发布时间：2026/9/16 23:32:30