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Infrabox

Register domains, cut the mailbox roster and publish SPF, DKIM, DMARC and MTA-STS in one run. Infrabox then ramps each sender and watches the blocklists while you stay on

  • No credit card
  • Setup in 6 minutes
  • Cancel anytime

3,400+ outbound teams run their sending fleet on Infrabox

app.infrabox.software/fleetDemo
getoutbound.coregistered
reachpilot.ioregistered
northloop.devregistered
signalcrest.comregistered
4 domains · 40 TLDs searchedStep 1 of 4

Trusted by 3,400+ outbound teams running their sending fleets on Infrabox

How it works

Four steps from an empty account to an authenticated first send

Nobody opens a zone editor, keeps a spreadsheet of DKIM selectors, or waits on a registrar ticket. You describe the fleet you want; the run builds it.

  1. 1

    Buy or attach the domains

    Search availability across 40+ TLDs, buy in bulk, or attach domains you already run. Nameservers point at Infrabox and the zone becomes ours to write.

    ~90 seconds
  2. 2

    Cut the whole roster at once

    Set mailboxes-per-domain and a naming pattern. Accounts, aliases, signatures and profile photos are created in one job, not one at a time.

    ~3 minutes
  3. 3

    Records publish and resolve

    SPF, DKIM, DMARC, MTA-STS and your own tracking CNAME are generated, written into the zone, then queried back to confirm they actually resolve.

    ~40 seconds
  4. 4

    Ramp, watch, send

    Warmup opens on your private peer network while Reputation Radar watches blocklists and placement. Point your sequencer at the fleet and go.

    Continuous
Provisioning run #4821Started 6 min ago
Overall progress0%
  • northloop.dev15 mailboxes · SPF, DKIM, DMARC live
  • reachpilot.io8 mailboxes · SPF, DKIM, DMARC live
  • signalcrest.compublishing DKIM selector…
  • vantagegrid.coqueued
  • kestrellabs.ioqueued
Platform

Fleet-wide by default. Never one domain at a time.

Registration, zone records, mailboxes, auth, ramp and blocklist watch share one piece of state. Change a naming pattern once and three hundred mailboxes follow.

Bought here or owned for years

Attach domains you already run or register new ones in bulk. From the first record onward, neither one is a special case.

Connect
my domain

2 connected

Purchase
domains

6 in cart

DNS you never hand-edit

Records, forwarding with tagging and masked redirects change across hundreds of domains in a single action: seconds, not a support ticket.

DNS recordsSettingsMailboxes
TXT @60s
TXT ibx._domainkey80s
TXT _dmarc100s
CNAME link120s

Domain forwarding

Point traffic from new domains to your main site.

infrabox.software
Enable domain masking

Auth records that re-prove themselves

SPF, DKIM, DMARC, MTA-STS and BIMI are generated per domain, published for you, then re-queried every six hours, because the record that breaks you is the one somebody edited two quarters ago.

SPFDMARCDKIMMTA-STSBIMI

A roster, not a mailbox

Set a pattern and a headcount. Accounts, aliases, signatures and photos land in one job, and each one enrolls in warmup as it is created.

Creating mailboxes42 of 60
PRpriya.raman@
MKmarcus.kell@
ATana.torres@
DSdevon.shaw@

One workspace per client, billed apart

Domains, invoices and access live inside a single client workspace. Nothing crosses over, including a bad month on somebody else's sender.

Search workspaces⌘K
NLNorthloop4 domains
SCSignalcrest6 domains
KLKestrel Labs3 domains

A ramp curve, not a volume switch

Mailboxes send and reply inside your own peer network, climbing week by week on a curve a receiving server reads as growth.

Warmup rampWeek 9 of 12

Reputation Radar

Every domain and IP checked against the major public blocklists every 15 minutes. The listing reaches you before it reaches your prospects.

0blocklist entries

Blast radius stops at the workspace

Domains, mailboxes, billing and permissions are partitioned per client, so one burned sender costs you one workspace, not your whole book of business.

Northloop

18 mailboxes · isolated

Signalcrest

12 mailboxes · isolated

Orbitline

24 mailboxes · isolated

Kestrel

9 mailboxes · isolated

Client onboarding becomes a deploy

A REST API and signed webhooks cover every action in the console, so a new client is a script that runs rather than a checklist somebody works through.

infrabox-cli
$ infrabox fleets create \
  --domain northloop.dev \
  --mailboxes 15 \
  --warmup

✓ domain registered
✓ 15 mailboxes provisioned
✓ SPF · DKIM · DMARC verified

The registrant on every domain is you.

Domains are registered to your legal entity and unlock for transfer on request. Mailboxes export over standard IMAP. If you leave, the fleet leaves with you. Infrastructure you cannot take with you is not infrastructure.

See what gets published
  • RegistrantYour entity
  • Mailbox exportStandard IMAP
  • Exit feeNone
By the numbers

Infrastructure that measures up

Measured across every fleet on Infrabox, trailing 90 days.

0.0M+

Mailboxes provisioned

0K+

Domains under management

0 min

Median time to first send

0.0%

Median inbox placement

Deliverability

Reputation slips quietly. This is the tripwire.

By the time replies dry up, the cause is usually weeks old. Infrabox shows the score, the records underneath it and the exact change that moved it, per domain, every day.

  • Record drift

    SPF, DKIM, DMARC, MTA-STS and BIMI are re-queried every six hours, so an edit made at your DNS host arrives as an alert, not as a bounce.

  • Domain hygiene

    Registration age, redirect chains and the tracking-domain certificate are checked before a domain is allowed to carry its first send.

  • Per-mailbox caps

    The rotation engine holds every mailbox to its daily ceiling, so no single sender outruns the reputation it has actually earned.

  • Seed panel proof

    A seed campaign to a receiving panel tells you which folder you land in before the real list ever sees the message.

Deliverability reportLive
0Sender score
  • Inbox99.2%
  • Promotions0.5%
  • Spam0.04%
  • Bounce0.31%

0 blocklist entries across 4 domains and 45 mailboxes

Integrations

Mailboxes land in your sequencer already warm

Rosters push into your sequencer, engagement syncs back to the CRM, and every provisioning and reputation event streams wherever you want it, natively or over the API.

CadenceSequencer
ReachpilotSequencer
Northloop CRMCRM
SignalcrestAnalytics
Vantage GridCRM
KestrelEnrichment
OrbitlineWarmup
PipeworksAutomation
TesseraAnalytics
GroundwireEnrichment
  • Sequencers
  • CRM
  • Warmup
  • Analytics
  • Enrichment
  • Webhooks
Browse all 24 connectors
Copilot

Six chores nobody schedules time for

Naming, diagnosing, sizing and testing are the work that quietly eats a week. Six assistants do them against your live fleet instead.

Domain Genie

Give it a keyword and get a shortlist already checked against the registry: priced, scored, and registrable in a single batch.

  • Availability checked live
  • Priced and scored per name
  • Register the batch in one step
app.infrabox / domains / genie
northloopAI
trynorthloop.com$11.20
northloop.dev$13.90
getnorthloop.io$34.00
northloop.comTaken

Bounce Doctor

Paste the SMTP rejection. You get the actual cause, the record that is wrong and a one-click fix, instead of a decade-old forum thread.

  • Plain-language cause
  • The exact record at fault
  • One-click fix
app.infrabox / deliverability / bounces

550 5.7.26 Unauthenticated email from northloop.dev is not accepted

Diagnosis

DKIM selector missing on the sending subdomain. Publish ibx._domainkey and re-verify.

Fix automatically

Mailbox Namer

Handles that match the domain and the team, with collisions resolved and per-client overrides, so a hundred addresses never read as generated.

app.infrabox / mailboxes / names
PRpriya.raman@first.lastReady
PRp.raman@f.lastReady
PRpriyar@firstlReady

Capacity Planner

Work backward from a campaign size to the mailbox count and the ramp that keeps every sender under a safe daily volume.

app.infrabox / fleet / capacity
Week 1216
Week 2408
Week 3672
Week 4936
Week 51128

Safe daily volume per mailbox

Sender Rotation

Volume spreads across the roster automatically, and any mailbox that drops below its reputation floor leaves the pool until it recovers.

app.infrabox / sending / rotation
ABCDE45in rotation

Placement Tests

A seed send to a panel of receiving accounts tells you the folder before your real list finds it out for you.

app.infrabox / tests / placement
Primary inbox92%
Promotions6%
Spam2%

Seed panel · 40 receiving accounts

Customers

Real fleets. Real placement.

Agencies, platform teams and founders who stopped babysitting DNS and got their sending back.

“We were rebuilding the same DNS checklist for every new client. Now a workspace is provisioned before the kickoff call ends.”
Priya RamanHead of Delivery, Northloop
“Placement went from somewhere around 70% to consistently above 98%. The difference was authentication we did not know was broken.”
Marcus KellFounder, Reachpilot
“The rotation logic quietly pulled two mailboxes out of the pool before either of them bounced. That alone paid for the year.”
Ana TorresGrowth Lead, Signalcrest
“Per-client isolation was the blocker for us. One workspace going sideways used to be everyone's problem. Not any more.”
Devon ShawOperations Director, Vantage Grid
“I provision 40 mailboxes from a script now. Onboarding a client is a deploy, not a two-day project with a spreadsheet.”
Iris NakamuraPlatform Engineer, Kestrel Labs
“The bounce diagnostics are the feature I did not know I wanted. It tells you the record that is wrong instead of a status code.”
Tomas WeberDemand Gen, Orbitline
“Six weeks of warmup handled without me touching it once, and the ramp curve actually looks like a real team growing.”
Lena FitchOutbound Manager, Pipeworks
“We moved 180 mailboxes across in an afternoon. Everything exported cleanly, which told me the ownership claims were real.”
Samir HaddadRevOps, Groundwire
Pricing

You size the fleet, not the feature list

No tier withholds authentication, warmup or monitoring. The only variable is mailbox count, and the per-mailbox rate falls as the fleet grows.

Starter

One operator, one book of prospects, a first channel to prove.

$39/month

10 mailboxes included

$3.50 per extra mailbox

Start free trial
  • Unlimited domains
  • SPF, DKIM, DMARC, MTA-STS
  • Warmup from day one
  • Email support
Most popular

Growth

Several campaigns and a handful of clients running in parallel.

$99/month

30 mailboxes included

$3.25 per extra mailbox

Start free trial
  • Everything in Starter
  • Per-client workspaces
  • Reputation Radar
  • Seed placement tests
  • Priority support

Scale

Agencies and platforms running fleets for a book of clients.

$299/month

100 mailboxes included

$3.00 per extra mailbox

Start free trial
  • Everything in Growth
  • REST API + signed webhooks
  • Role-based access
  • Audit log
  • Dedicated IP pool option

Past 500 mailboxes, or need dedicated IP pools, SSO and a signed DPA? Enterprise is scoped per fleet.

Compare all plansTalk to sales
FAQ

The questions that come up at the end

If the answer you need is not here, it is probably specific to your fleet. Ask someone who runs them for a living.

The domains: they are registered to your legal entity, and transfer locks come off on request. The mailboxes export over standard IMAP, so the history comes too. There is no exit fee and no proprietary format to unwind first.

Domain reputation does, because it is attached to the domain and the records on it, and both stay yours. IP reputation does not travel. Moving to a new sending IP anywhere means ramping again, with us or with anyone else. Be careful with a vendor who claims otherwise.

Reputation Radar checks every domain and IP you own against the major public lists every 15 minutes. A listing pulls that sender out of rotation automatically, alerts you, and shows the delisting path for that specific list. The rest of the fleet keeps sending.

Caps are enforced per mailbox rather than per domain. A new mailbox opens at four to six sends a day and reaches roughly 30–50 a day at steady state, with the ceiling set by your plan. The rotation engine enforces it, so a sequencer cannot push a mailbox past its own ramp.

600 requests per minute on the standard plan, with the remaining budget returned in an X-RateLimit-Remaining header on every response. Provisioning calls accept an idempotency key with a 24-hour window, and long jobs return a job ID immediately and finish asynchronously.

Yes. Point the nameservers at Infrabox and we write the zone directly, or leave DNS with your provider and we hand you the exact records to publish. Verification and monitoring run identically either way. Only the write step differs.

Yes. Existing mailboxes are imported and enrolled in warmup and monitoring without recreating them, and ones with real sending history skip the early ramp stages instead of restarting at four sends a day.

No, and that is the point of the workspace boundary. Domains, mailboxes, billing and permissions are partitioned per client, sending is spread across the roster, and any mailbox that drops below its reputation floor leaves the pool on its own.

On the major workspace-grade providers, or on dedicated SMTP servers we run in US and EU regions. You choose the provider class per domain; account creation, DNS and authentication are identical either way.

Plans bill monthly, quarterly or yearly with a mailbox allowance included, and extras bill at a per-mailbox rate that drops as you scale. Upgrades prorate immediately, downgrades take effect at renewal, and first purchases carry a 14-day refund window.

Still have questions?

Talk to the people who run sending fleets every day.

Contact usRead the guides
Free for 14 days

Stop hand-building sending infrastructure.

Register a domain, cut ten mailboxes and watch the records resolve, all inside the next ten minutes. Keep the fleet if the numbers hold up.

Start building freeSee pricing
  • You are the legal registrant
  • Cancel any time
  • IMAP export, no exit fee