Deliverability, built into every mailbox

Arcinbox checks every email before it leaves, pauses a mailbox
before it burns, and tells you what broke and why.

Book a deliverability audit

Every domain set up for sending.

Paste the domains you want to buy. Arcinbox registers them and publishes SPF, DKIM, DMARC and MX on every one.

See how

SEND FROM ANY OF THEM. WE WATCH ALL OF THEM.

Google Workspace Microsoft 365 Microsoft Azure Custom SMTP

HOW A GOOD CAMPAIGN GOES QUIET

Replies dried up in week three.
Nobody can tell you why.

Monday

An old list goes out.

Plenty of the people on it changed jobs since. Every bounce counts against the mailbox that sent it, and nothing stopped them going out.

Wednesday

Your tracking link gets listed.

Every email carrying it now looks like spam, including the ones already queued for tomorrow.

Friday

Google suspends two mailboxes.

Nobody tells you. You find out next week from a sequencer error, after days of sends that went nowhere.

And every dashboard you have still says healthy.

WHAT YOU TRY NEXT

So you start guessing.

Rewrite the copy
Cut daily volume
Buy fresh domains
Switch providers

Each guess costs a week. None of them looks at the email that did the damage, because by the time replies dry up, that email went out weeks ago.

The damage happens when you send.
That's where Arcinbox checks.

ARCWATCH

Watches every mailbox, guards every send, heals what breaks

Each problem arrives once, with its cause and what ArcWatch already did about it.

Watch
Watches every domain, mailbox and link, all day.
Send check
Guards every send. Bad email stops before it leaves.
Self-heal
Heals what breaks: pauses, reconnects and replaces on its own.

ARCWATCH · WATCH

Know what broke
while it still matters

ArcWatch keeps an eye on every account, domain and reply,
so a problem has a name before it costs you a month.

Suspensions, spotted within the hour

When Google suspends a mailbox, you see it on your screen, not in a sequencer error next week.

Records that stay right

Arcinbox sets up SPF, DKIM and DMARC on every domain and checks them again later, so a broken record never sits unnoticed.

How domain setup works

Listings, flagged the same day

If a sending domain or a link you use lands on a blocklist, you see which one and what to do next.

How ArcWatch works

ArcWatch · Send check

Stop the damage before the email leaves

ArcWatch checks every email before it goes. The ones that would hurt your reputation stop there.

Book a deliverability audit

sam@getacme.example is sendingChecking

Won't bounceDead addresses stopped

Clean linksListed links stopped

sam@getacme.exampleOutgoing email

Tojo@northwind.exampleSent

Toana@oldlist.exampleStopped, would bounce

Linkgo.getacme.example/demoStopped, listed link

Toli@contoso.exampleSent

Checked before sending2 of 4 stopped

ExplainedWhy each one stopped

DeliveredThe rest goes out as normal

Stopped, not reported

A report tells you what hurt you last week. The check stops it from leaving today.

Nothing to change

Keep your sequencer, your copy and your schedule. The check runs on every email by itself.

A reason for every stop

Each stopped email comes back with why, so you clean the list instead of guessing.

ArcWatch · Self-heal

Pause a mailbox before it burns

When a mailbox starts to go wrong, ArcWatch pauses it, holds its email, and picks up again once it recovers.

Book a deliverability audit

getacme.exampleGoogle mailboxes

12 mailboxesAll sending

tryacme.exampleGoogle mailboxes

12 mailboxes1 paused

maya@tryacme.example paused at 10:40. Bounces from its last list ran high.

46 emails waitingResumes on its ownDomain unaffected

meetacme.exampleMicrosoft mailboxes

3 mailboxes1 replaced

Waiting, not lost

Email from a paused mailbox waits. It goes out once the mailbox is healthy again.

Back on its own

Nobody files a ticket. The pause lifts as soon as the mailbox recovers.

Every pause explained

You see which mailbox paused, when, and why, in one line.

A burnt mailbox is our problem.
If one gets suspended anyway, we replace it at no charge.

$0to replace a
burnt mailbox

Keep the sequencer
you already run

Arcinbox sits under your sending tool, not in place of it. Campaigns stay where they are. We look after the mailboxes they send from.

Instantly
Smartlead
EmailBison
PlusVibe
lemlist
Saleshandy
Woodpecker
Apollo.io
Salesforge
Snov.io

WHO IT'S FOR

For whoever gets asked
why replies dropped

Agencies, sales teams and founders who send every day
and can't afford a quiet month.

Agencies

One client's bad list stays that client's problem. Each client gets a separate workspace and their own domains.

Sales teams

Reps keep their sequencer and never touch DNS. You see every rep's mailboxes on one screen.

Founders

You are the outbound team. Arcinbox is the deliverability hire you skipped.

Operations

Hundreds of domains, and one list of what needs you today.

Growing teams

Add Microsoft next to Google without redoing any setup.

Three steps, then it runs itself

Nothing to install. Talk to us first if you're moving a big fleet.

Buy mailboxes

Pick Google, Microsoft, Azure or custom SMTP, and the domains you want to send from.

Connect your sequencer

Choose your tool and the mailboxes arrive in it, ready to use.

Send as usual

Arcinbox checks every email on its way out. You hear from us when something needs you.

One price per mailbox

Pay for the mailbox.
Deliverability comes with it.

Every check on this page is included. There are no plans to pick and no add-ons.

Google WorkspaceStart here

$2.50/ mailbox / mo

Google Workspace mailboxes with every check included.

Coming soon

Every email checked before it sends
Free replacement for burnt mailboxes
Three weeks of warmup included

Microsoft 365

$2.50/ mailbox / mo

A second provider, so one bad week doesn't stop everything.

Coming soon

Every email checked before it sends
Free replacement for burnt mailboxes
Three weeks of warmup included

Azure tenants

$30/ tenant / mo

One tenant per client or brand, billed per tenant.

Coming soon

Its own accounts and settings
Blocklist and DNS monitoring
Three weeks of warmup included

Custom SMTP

Custombuilt around you

Sized with you around your volume and IPs.

Plan a setup

Built around your volume and IPs
Blocklist and DNS monitoring
Three weeks of warmup included

Google and Microsoft are priced per mailbox. Azure is priced per tenant, with capacity and licensing confirmed at checkout.

Questions

What people ask
before they switch

Short answers to the questions we hear most.

Is Arcinbox a sequencer?

No. Your sequencer still writes and schedules every campaign. Arcinbox supplies the mailboxes it sends from and looks after their deliverability.

Will my email still come from Google or Microsoft?

Yes. Recipients get a normal email from your provider, signed as you. Nothing about it changes for the person reading it.

Do you read my emails?

No. Nobody at Arcinbox reads your campaigns. The check looks for problems, not at what you wrote.

What if a mailbox gets suspended anyway?

We replace it free, and you usually hear about it from us within the hour, before your sequencer starts throwing errors.

How soon can I start sending?

Mailboxes are ready the day you buy them. Give new domains their three weeks of warmup before a campaign goes out. The dashboard counts down for you.

What does an Azure tenant include?

One tenant for $30 a month, rather than one mailbox. Capacity, licensing and sending limits depend on the setup and are confirmed at checkout.

Stop guessing why
replies dropped

Find out the hour something breaks,
not the month after.

Book a deliverability auditGoogle & Microsoft from $2.50 / mailbox / month

FOR YOUR AI AGENT

Your agent sets it up.
Arcinbox keeps it sending.

Add the Arcinbox MCP server to Claude, Codex, Cursor or any MCP client. Your agent buys the domains and mailboxes, and Arcinbox still checks every email they send.

Book a discovery call

1Onboard your agent

Claude CodeIn your terminal CodexIn the Codex app CursorIn the Cursor agent OpenClawIn the OpenClaw app

Opens your agent with a prompt to read arcinbox.com/index.md and plan your setup with you.

2Add the MCP server

claude mcp add --transport http arcinbox https://mcp.arcinbox.com/mcp

In Claude Code, run this in your terminal. In the Claude app, add the same URL under Settings, Connectors. Any other MCP client takes the same URL, and you sign in to Arcinbox once in the browser.

3Then ask it

Use Arcinbox to buy 40 new domains with 3 Google mailboxes each. Add all of them to Smartlead and tell me when they are ready.

SAME ORDER, TWO WAYS

What you click, your agent can call

Drag the line. On the left, 120 mailboxes bought in the dashboard. On the right, an agent places the same order through the Arcinbox MCP server.

You, in the dashboardOrders / New order

New order

ProviderGoogleMicrosoft

New domains40

Mailboxes per domain3

Add toSmartlead

Mailboxes120

Buy 120 mailboxes

Order 1042Setting up

Domains registered40 of 40

DNS records verified40 of 40

Mailboxes created84 of 120

Added to SmartleadWaiting

Started at 10:02

agent sessionYour agent, over MCP

you

Buy 40 new domains with 3 Google mailboxes each and add them to Smartlead.

MCParcinbox.quote_domains

40 of 40 available

MCParcinbox.create_launch

{
  "provider": "google",
  "domains": [
    {
      "name": "acmemail.example",
      "mailboxes": [
        { "local_part": "alex", "first_name": "Alex" },
        { "local_part": "maya", "first_name": "Maya" },
        { "local_part": "sam", "first_name": "Sam" }
      ]
    },
    … 39 more domains
  ],
  "sync": { "connection_id": "con_smartlead" }
}

RESULTcreate_launch

{
  "id": "lch_7Qm2",
  "status": "processing",
  "domains": 40,
  "mailboxes": 120,
  "sync": "pending"
}

MCParcinbox.get_launch

{ "id": "lch_7Qm2", "status": "completed" }

agent

Done. 120 mailboxes on 40 domains, all in Smartlead.

THE MCP SERVER

Every step is one tool

Add the server once and your agent sees these tools. Each is marked read, write or paid, so you decide which ones need your yes.

Set up

create_launchPAID
Buy or link domains, create the mailboxes and sync them, in one call.
quote_domainsREAD
Availability and price for up to 50 domains.
add_mailboxesPAID
More mailboxes on domains you already have.

Connect

connect_toolWRITE
Connect Smartlead or Instantly.
sync_mailboxesWRITE
Add live mailboxes to a connected sending tool.

Check

check_domainREAD
Records, blocklist results and mailbox health for one domain.
list_mailboxesREAD
Every mailbox, with its setup progress and any suspension.

Follow up

get_launchREAD
Where an order stands, domain by domain.
add_callbackWRITE
Get told at your own URL when something changes.

mailbox.suspendedmailbox.status_changeddomain.status_changedlaunch.status_changedsync.status_changed

The same tools are a REST API with an OpenAPI spec, for code that is not an agent.

GUARDRAILS

Safe to hand to an agent

Agents retry, loop and run at 3am. The server is built for that.

Retries never buy twice.

If your agent repeats an order, it gets the first answer back instead of a second bill.

It spends only what you put in.

Orders are paid from a wallet you top up. When the balance is short, the API returns the exact shortfall and charges nothing.

Told when to wait.

A busy agent is told how long to wait, not handed an error it has to guess at.

Errors it can act on.

Every error carries a code, a message and the field that caused it.

Hand the setup to your agent

Book a discovery call and we will set up a workspace your agent can use.

Book a discovery call

Deliverability, built into every mailbox

Replies dried up in week three.Nobody can tell you why.

An old list goes out.

Your tracking link gets listed.

Google suspends two mailboxes.

So you start guessing.

Watches every mailbox, guards every send, heals what breaks

Know what brokewhile it still matters

Suspensions, spotted within the hour

Records that stay right

Listings, flagged the same day

Stop the damage before the email leaves

Stopped, not reported

Nothing to change

A reason for every stop

Pause a mailbox before it burns

Waiting, not lost

Back on its own

Every pause explained

Keep the sequenceryou already run

For whoever gets askedwhy replies dropped

Agencies

Sales teams

Founders

Operations

Growing teams

Three steps, then it runs itself

Buy mailboxes

Connect your sequencer

Send as usual

Pay for the mailbox.Deliverability comes with it.

What people askbefore they switch

Stop guessing whyreplies dropped

Your agent sets it up.Arcinbox keeps it sending.

What you click, your agent can call

Every step is one tool

Set up

Connect

Check

Follow up

Safe to hand to an agent

Retries never buy twice.

It spends only what you put in.

Told when to wait.

Errors it can act on.

Hand the setup to your agent

Replies dried up in week three.
Nobody can tell you why.

Know what broke
while it still matters

Keep the sequencer
you already run

For whoever gets asked
why replies dropped

Pay for the mailbox.
Deliverability comes with it.

What people ask
before they switch

Stop guessing why
replies dropped

Your agent sets it up.
Arcinbox keeps it sending.