InboxSignal

What it does

Your cold emails aren't getting replies, but you don't know why. InboxSignal diagnoses exactly what's wrong. Paste your email, add a line about your prospect, and get a score, a breakdown of what's failing, real fixes, a full rewrite, and subject line options. FREE, NO Card, just 30 seconds.

• 
  Email Warm-Up Tool by Reply2021 · ▲325

  Make sure your emails land in the inbox, not spam

• 
  Cold Email Analyzer by Mailshake2018 · ▲222

  Real-time analysis of email subject lines and copy

• 
  Quicklines2022 · ▲138

  Cold email personalized AI icebreakers to get more responses

• 
  ProxelionMay 2026 · proxelion.com · ▲2

  AI cold emails that actually get replies

• 
  Make senders work to get into your inboxJul 2026 · captchainbox.com · ▲44

  Hi HN :) really excited to share this with you. The one thing AI reliably does is generate noise. Half the tools I see launch are just machines for producing more noise across more channels. And people are starting to see this in the form of emails in their inboxes as spam filters are struggling. There used to be a useful signal in email: the effort a sender put into customizing a message was a rough proxy for how relevant it actually was. AI killed that. Now it's customized slop with the appearance of effort with none of the cost. It is painful that the open internet / open channels…

• 
  SendlyioJun 2026 · sendlyio.com · ▲14

  Cold email that actually replies

• 
  Browzer▲426

  Put your technical content on autopilot

  Growth · 14d ago · trybrowzer.com

• 
  AstraPixels▲267

  ​​A pixel-art solar system at its real current positions.​

  Growth · 30d ago · astrapixels.com

• 
  Brew ▲905

  Like Claude design for email marketing

  AI · May 2026 · brew.new

• 
  Kilo Code for VS Code▲897

  Parallel agents, diff reviewer, and multi-model comparisons

  Dev tools · May 2026 · kilo.ai

• 
  StoreClaw▲805

  Grow your store profits with agents that know how to sell

  AI · May 2026 · storeclaw.ai

• 
  PollyReach▲796

  Give your agent a real number and voice to make calls.

  AI · May 2026 · pollyreach.ai

• NW
  Needle: We Distilled Gemini Tool Calling into a 26M Model▲776

  Hey HN, Henry here from Cactus. We open-sourced Needle, a 26M parameter function-calling (tool use) model. It runs at 6000 tok/s prefill and 1200 tok/s decode on consumer devices. We were always frustrated by the little effort made towards building agentic models that run on budget phones, so we conducted investigations that led to an observation: agentic experiences are built upon tool calling, and massive models are overkill for it. Tool calling is fundamentally retrieval-and-assembly (match query to tool name, extract argument values, emit JSON), not reasoning. Cross-attention…

  Life & fun · May 2026 · github.com

• FM
  Files.md – Open-source alternative to Obsidian▲730

  Dev tools · May 2026 · github.com