5gbinbox B2B & Enterprise only

// business email, rebuilt around relationships

One platform for every inbox, every introduction, every integration.

5gbinbox gives organizations a single workspace to run many inboxes, see exactly who introduced whom, and stream every email event into the tools your teams already use.

multi-inbox introduction graph webhooks REST API
click to send a ripple

Built for business teams

01 / multi-inbox

Run every inbox your business has from one place

Team addresses, departments, brands and personal mailboxes live side by side in 5gbinbox. Switch in a click, or work them all at once in a unified view.

  • ∑
    Unified viewRead and reply across all inboxes in one stream, always sending from the right address.
  • ⇄
    Shared inboxes & assignmentAssign threads to teammates, leave internal notes, and avoid double replies.
  • ⚑
    Routing rulesRoute mail between inboxes by sender, domain, keyword or relationship.
02 / introduction graph

See who introduced whom, across every thread

5gbinbox notices introductions as they happen in email and builds a living tree of your relationships: who brought each contact in, through whom, and when.

  • ⌥
    Introduction treeFollow any contact back to the person who first connected you, step by step.
  • →
    Warm pathsFind the shortest chain of real introductions to the person you want to reach.
  • ★
    Credit & referralsKnow which partners and colleagues bring the most valuable relationships.
03 / webhooks & integrations

Every email event, streamed to your systems

Subscribe to real-time webhooks for messages, threads, contacts and introductions, or use the REST API to build on top of 5gbinbox directly.

message.receivedmessage.sentthread.assigned contact.createdcontact.introducedrule.matched
CRMSync contacts & intros
Team chatPost alerts to channels
HelpdeskTurn threads into tickets
Data warehouseExport event history
AutomationNo-code workflows
Your own appsREST API & signed hooks
# signed webhook delivered to your endpoint
POST /hooks/5gbinbox
X-5gbinbox-Signature: t=1760521331,v1=9f2c…

{
  "event": "contact.introduced",
  "inbox": "partners@acme.example",
  "introducer": "omar@halcyon.example",
  "introduced": "ravi@orbit.example",
  "to": "dana@northwind.example",
  "depth": 2,
  "thread_id": "thr_8f2c1a",
  "occurred_at": "2026-10-15T09:42:11Z"
}
and more

Built for the way business teams work

Features designed for organizations, from the first introduction to the signed deal.

timeline

Relationship timeline

Every email, intro and handoff with a contact, shown in one chronological view.

rules

Smart routing

Conditional rules that tag, forward, assign or fire a webhook as soon as mail arrives.

roles

Roles & permissions

Control who can read, send from or administer each inbox in your organization.

search

Search across inboxes

Find any thread, attachment or person across every inbox you have access to.

domains

Multiple domains

Bring every brand and subsidiary domain into a single 5gbinbox workspace.

audit

Audit log

A complete record of admin actions and inbox access for internal review.

Business customers only. 5gbinbox does not offer personal or free accounts. Workspaces are set up for organizations under a business agreement.