New: the Unified InboxSee how
Built for · Agencies

One Unified Inbox for every client's replies.

Every reply from every client and every sending tool lands in one view. Each client gets its own workspace, inbox agents, knowledge base, calendar, and Slack channel. The agents reply in under 5 minutes, follow up, and book the meeting.

Unlimited workspaces on the Agency plan and unlimited seats on every plan. Adding a client never adds a per-seat fee.

Set up your Unified Inbox
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  • 50 free replies
  • No credit card
  • Unlimited workspaces on Agency
Unified Inbox
Example view
Client workspaces
All clients (20) 61
A Acme Roofing 14
N Northwind Logistics 9
B Brightline Dental 6
H Harbor Fitness 4
+ 16 more workspaces
  • Jordan Meyer Acme Roofing
    Thursday at 10:30 works. Talk then.
    Meeting booked
  • Emily Tran Northwind Logistics
    Can you send over a case study first?
    Replied · auto
  • Lena Schulz Harbor Fitness
    Yes, interested. Who should I talk to?
    Needs approval
  • Omar Haddad Brightline Dental
    We're mid-contract until Q2. Circle back then?
    Follow-up · Apr 2
  • Alex Walker Acme Roofing
    What does pricing look like for three locations?
    Replied · auto
Replies come in from Smartlead Instantly Email Bison HeyReach Client names are fictional.
One workspace per client

Shared inbox. Separate everything else.

Your team works from one Unified Inbox. Behind it, every client runs in its own workspace, so one client's offer, calendar, and rules never leak into another's.

Inbox agents in a workspace only know that client. They answer from that client's knowledge base and book onto that client's calendar.

A
Acme Roofing
Client workspace · example
Live
  • Inbox agents
    Workspace Agent on. One agent answers every reply in this workspace.
  • Knowledge base
    The client's offer, pricing guidance, FAQs, and case studies.
  • Calendar
    The client's own Google Calendar or Outlook, connected with a link.
  • Slack channel
    Approvals, sent replies, and booked meetings post to #acme-roofing.
  • CRM
    The client's GoHighLevel sub-account, with its own stage mapping.
  • Approval rules
    Interested waits for a human. Routine categories auto-send.

Built for the way agencies actually run

Many clients, many sending tools, a small team. The Unified Inbox is shaped around that.

One inbox across every client and tool

Smartlead, Instantly, Email Bison, PlusVibe, Lemlist, HeyReach, Aimfox, Expandi, GetSales, and Gmail all feed the same view. Each conversation shows the lead, the workspace, the category, and the agent that handled it. Filter to one client or look at all of them.

What is a Unified Inbox?

A Workspace Agent per client

Run one workspace per client and turn on the Workspace Agent. A single agent answers every reply in that workspace with no trigger keywords. Several clients inside one sending workspace? Route replies by trigger keyword instead.

See agent scopes

Approve or take over, client by client

Approval rules are set per inbox agent. Start a new client with every draft on Require Approval and leave a mature client on auto. Open any thread to reply directly or take the conversation over. Approve from the app, from the client Slack channel, or through MCP.

How approvals work

Reporting that stays per client

Every reply, category, and booked meeting is kept inside the client workspace. The client Slack channel is a live feed of what was sent and what got booked. Pull a daily summary per workspace through the MCP connector, or push events into your own reports with webhooks and the API.

Pricing that fits an agency

Client 21 costs nothing to add.

Every plan includes unlimited team members and inbox agents, and the Agency plan includes unlimited workspaces. Sign a client, create a workspace, invite whoever needs access.

You pay for agent credits. Understanding a reply costs half a credit. Drafting a reply costs one. Calendar invites cost nothing.

See pricing
What it costs to add a client
  • A new client workspace $0
  • A seat for every account manager $0
  • Another inbox agent $0
  • Calendar invites for booked meetings 0 credits
You pay for: agent credits, used when an inbox agent reads or drafts a reply.

How it works for agencies

Onboarding a client is four steps. Your sending tools keep sending. Nothing else changes.

1

Create the client workspace

Add a workspace for the client and connect the sending tool their campaigns run on. Replies start landing in your Unified Inbox, tagged with that client.

2

Train the agent on their offer

Paste the client's website and Underfive drafts the company description. Add value propositions, pricing guidance, FAQs, and case studies. Every client gets its own knowledge base.

3

Connect their calendar and channel

Send the client a link. They connect Google Calendar or Outlook without an Underfive login. Pick the Slack channel this workspace posts to.

4

Set approvals and launch

Turn on the Workspace Agent. Keep every category on Require Approval for the first week if you like, then move categories to Auto-send as you trust the replies.

Twenty clients, one place to look

The work that grows with every client is inbox work. This is what changes.

An inbox per tool, per client

How most agencies handle replies today
  • A separate inbox in every sending tool, for every client
  • Replies wait until someone logs in to that tool
  • Each account manager answers in their own style
  • Scheduling goes back and forth by hand
  • A new client means another login to check every morning

One Unified Inbox

With inbox agents in every client workspace
Underfive
  • Every client's replies in one Unified Inbox
  • Inbox agents reply in under 5 minutes, 24/7
  • Each client's agent answers from that client's knowledge base
  • Meetings booked straight onto the client's calendar
  • A new client is one more workspace, with no extra fee
"We are now using Underfive full-time for our inbox management, and we wanted to thank you for being so quick and attentive to our feature requests and bug reports. You guys are really on the ball and have gotten the product to a point that it's fulfilling our original vision."
Agency owner
Manages 20 client workspaces on Underfive

Unified Inbox for agencies FAQ

What is a Unified Inbox for lead gen agencies?

It is one view of every reply from every client and every sending tool. Underfive is a Unified Inbox with AI inbox agents inside it. Each client gets its own workspace, and the agents in that workspace reply in under 5 minutes, follow up, and book meetings on the client's calendar.

How do client workspaces work?

Create one workspace per client. Each workspace has its own inbox agents, knowledge base, calendar, Slack channel, and approval rules. The Unified Inbox still shows every client in one place, and you can filter down to a single client at any time.

Does adding a client or a teammate cost more?

No. Every plan includes unlimited team members and unlimited inbox agents. Workspaces grow with the plan: 1 on Professional, 5 on Growth, 10 on Business and unlimited on Agency. Plans are priced by agent credits, so you pay for replies handled, not for seats or clients.

What is the Workspace Agent?

It is the workspace-level agent scope. One inbox agent covers every reply in the workspace without trigger keywords. It is the best fit when each client has its own workspace in your sending tool.

What if several clients share one sending workspace?

Use trigger keywords. A client name, an email signature, or a sender name in the thread routes each reply to the right inbox agent, so every client still gets its own knowledge base and rules.

Can each client have its own calendar, Slack channel, and CRM?

Yes. Each workspace books onto its own Google Calendar or Outlook calendar, posts to its own Slack channel, and can connect its own GoHighLevel sub-account. Clients connect their calendar from a link and never need to log in to Underfive.

Can I review replies for a new client before they go out?

Yes. Approval rules are set per inbox agent. Put every reply category on Require Approval for a new client, then move categories to Auto-send as you gain confidence. You can approve, edit, or reject drafts from the app, from Slack, or through the MCP connector.

Which sending tools does it work with?

Smartlead, Instantly, Email Bison, PlusVibe, Lemlist, HeyReach, Aimfox, Expandi, GetSales, and Gmail. Replies go back out through the same tool and sender they arrived on, so threading and deliverability stay the same.

Related

Unified Inbox Inbox agents Agent scopes Approvals Meeting booking Smart follow-ups Pricing

Every client. One Unified Inbox.

Start with one client workspace. Your first 50 replies are free, and the next client costs nothing to add.

Set up your Unified Inbox Book a demo