EMAIL AND LINKEDIN. ANY MAILBOX. EVERY DEVICE.

Activate the Dark Pipeline.

Every revenue conversation, in HubSpot. SignalBox captures the email threads and LinkedIn messages your CRM never sees, runs server-side with no plugin or extension, resolves the contact details behind them, and drafts replies that know the deal. You review and approve from your phone. Nothing reaches HubSpot until you say so.

Activate yours→Let's chat→

Connect a mailbox, LinkedIn, or both. Minutes to set up. No plugins, no browser extensions.

65%
of sales activity never reaches CRM
CSO Insights
10–15%
pipeline lift from activated signals
SignalBox Research
25–32%
forecast accuracy improvement
Nucleus Research

Your pipeline has a blind spot, and it's costing you millions.

HubSpot is the operating system for ~280,000+ B2B sales teams. It tracks deals, automates workflows, and increasingly runs AI agents. But there's a structural problem it hasn't solved: critical deal context – the conversations, commitments, and relationship signals that drive revenue – never makes it into CRM where it can be acted on.

The platform's email extensions only work in desktop browsers. iPhone Mail handles 60% of global email opens.Outlook mobile, specialized email clients – none are supported. Even the platform's own support recommends different workflows depending on whether you're on mobile or desktop, and separate steps for contacts that already exist vs. new prospects. That's the behavioural overhead and friction your team absorbs every day. LinkedIn messages – the async coordination where commitments actually happen? Never connected to the deal record.And when a rep leaves, their inbox goes dark – every deal conversation in it dies with their account.

We call this Dark Pipeline– deal intelligence that exists in your team's communications but never reaches your system of record. Not a discipline problem. A structural gap. Teams that activate their Dark Pipeline see an estimated 10–15% pipeline lift– regardless of team size. And because reps never touch the process, you eliminate the CRM busywork they resent most – the manual logging, the nag emails, the guilt of knowing their pipeline data is incomplete.

How it works

01.Connect what you use. A mailbox (Microsoft 365, Gmail, or any IMAP provider), LinkedIn, or both. Everything runs server-side. No plugins, no browser extensions, no change to how your reps work.
02.SignalBox captures the conversations that matter. Email threads and LinkedIn DMs and InMail, matched to the right contact, company, and deal, with attachments carried across. Where HubSpot already logged a message, SignalBox enriches that record instead of duplicating it.
03.Context is assembled and a reply is drafted. SignalBox resolves the contact details behind a conversation and drafts a response using the full thread and the related CRM records. Drafts land in your normal Drafts folder.
04.You decide. A prioritized feed on desktop and mobile shows what needs a reply, a contact to add, or a follow-up worth making. Nothing is written to HubSpot until a person approves it.

Full-context, AI-drafted replies

Mailbox  →  ╮
             SignalBox  →  HubSpot
LinkedIn →  ╯

Human-in-the-Loop Control

        SignalBox
             ↓
Phone  →  YOU  ←  Watch
             ↑
        CRM System

What SignalBox does

Conversation capture

Email threads from Microsoft 365, Gmail, or any IMAP provider, and LinkedIn DMs and InMail, logged to the right contact, company, and deal with their attachments. Server-side, so it works from any device and any mail client, including the mobile clients browser extensions cannot reach. Existing history can be brought in as well as new conversations.

Contact data

Resolve the work email, phone, and company details behind a conversation, and keep the CRM record current as roles and employers change. Updates fill empty fields rather than overwriting what your team already knows.

AI-assisted drafting

Replies drafted from the entire thread plus the related CRM records, saved to your normal Drafts folder for you to review, edit, and send.

Decide and act

One prioritized feed on desktop and mobile: replies to send, contacts to add, follow-ups worth making. Each item clears once handled and the outcome is written back.

Common questions

HubSpot's email extensions only work in desktop browsers – the Gmail Chrome extension and the Outlook add-in. They don't run on iPhone Mail, Outlook mobile, or any mobile email client. Even the platform's own support recommends different workflows depending on whether you're on mobile or desktop, and different steps depending on whether a contact already exists in CRM.If your reps use their phones for email – and most do – there's a structural gap no browser extension can close. SignalBox captures server-side, regardless of device or client.
Call recording captures what happens on recorded calls. SignalBox captures the 80% of deal communication that never happens on a call– email threads and LinkedIn messages. They're complementary, not competitive. Most deals close through written communication that never gets recorded.
It's a capture problem, not a discipline problem. No process change makes reps log everything – and the harder you push, the more they resent the tool. SignalBox routes the signals that get missed regardless, without requiring any behavior change from your team. Happy sellers, happy customers.
No. SignalBox uses intelligent, pattern-based filteringto identify revenue-relevant signals. Deterministic rules classify incoming messages and apply consistent, predictable logic – routine scheduling, internal threads, marketing noise, and junk all get filtered out. Built-in deduplication ensures clean coexistence with what HubSpot already captured natively. The result is a cleaner, more actionable CRM system – not a noisier one. And nothing is written to HubSpot until a person approves it, so the filter is a first pass, not the last word.
No. SignalBox uses transient processing with upstream filtering– messages are classified, evaluated for revenue relevance, and routed immediately. Only relevant signals reach your CRM; everything else is discarded at source. Your CRM is the system of record. No vendor vault, no dual archive. Signal metadata is retained for analytics, but message content lives only in HubSpot.

Offering brave rev teams access

Start solo, bring the tribe when you're ready.

Let's chat→Activate yours→