Cold Email Infrastructure
Youremailsdeserve
betterthanspam.
Google & Microsoft mailboxes on US IPs, DNS done for you, warmed and wired into your sequencer in minutes. From $2.50/mailbox. That's it, that's the pitch.
- Ready to send in 30 minutes
- US/EU IPs only
- 98%+ inbox placement
Dear Customer Support Team,
I hope this message finds you well. I am writing to seek assistance regarding my recent order, #12345, placed on October 10, 2023.
Best regards,
Phoenix
Hi there,
It looks like our courier mixed up the order. Sorry about that!
Have requested the drop-off the correct item with you tomorrow.
Benefits of InboxStack
Provision, warm, and scale
cold email infrastructure
One Workspace for Every Mailbox
Google, Microsoft, Azure, and SMTP mailboxes live under one stack. Read, reply, and route from a single unified inbox. no tab graveyard.
Live in 7 Minutes, Not 7 Hours
Domains registered, DNS pushed, mailboxes provisioned automatically. Watch the live log instead of waiting on tickets.
Pre-Warmed Reputation
Skip the 14-day ramp. Pre-warmed mailboxes arrive with reputation baked in, ready to fire day one.
Deliverability You Can See
Inbox placement, bounce rates, and blacklist status. tracked live, surfaced before reply rates flatline.
Banned? Replaced Free
Lose a mailbox to a provider ban and we swap it. No tickets, no extra invoices, no waiting period.
Pre-warmed mailboxes
Skip the two-week warmup queue. Grab mailboxes with reputation already baked in and send from day one. Or use our native warmup. smart ramp from 2 to 40 emails/day with live inbox-vs-spam tracking.
StackGuard monitoring
24/7 blacklist scans, DNS drift detection, bounce tracking, and placement tests. You get pinged before deliverability tanks, not after your reply rate flatlines.
One domain, one workspace
Full isolation per domain. If one domain catches a ban, the rest of your stack doesn't even notice.
Unified inbox
Read and reply across every mailbox from one master inbox. Tab fatigue is not a personality trait.
Free unlimited replacements
Mailbox gets banned? We swap it. Free. Every time. No "contact support" loop.
- tryacme.ioavail.
- acmeinbox.comavail.
- hello-acme.ioavail.
AI domain finder
One keyword in, a shortlist of available, brandable domains out. Seconds, not Sunday afternoons.
Smart mailbox namer + persona photos
AI generates professional handles and studio-grade profile pictures in bulk. No more john.doe.sales.7@.
Bulk everything
CSV import, bulk profile edits, bulk exports. Built for 100 mailboxes, comfortable at 1,000.
API & webhooks
Headless infrastructure for SaaS and AI SDR products. Provision, monitor, and export programmatically. Whitelabel available. sell this under your own name.
50+ integrations
Instantly, Smartlead, ReachInbox, Reply, Lemlist, Apollo, EmailBison, Salesforge, Saleshandy, HubSpot, Salesforce, and friends. OAuth, not app-password archaeology.
“InboxStackrebuiltouroutboundinfrastructureovernight.Wewentfrom61%inboxplacementto96%intwoweeks,whilescalingfrom30to300mailboxeswithoutasingledeliverabilityfire.”
Platform Showcase
One platform for every mailbox, domain, and sequencer
Live in ~7 minutes
Domains registered, DNS pushed, mailboxes spun up automatically. Watch the live log instead of opening tickets.
Isolation by design
One domain per workspace. If a single domain catches a ban, the rest of your stack doesn't even flinch.
One unified inbox
Read and reply across every Google, Microsoft, and SMTP mailbox from one workspace.
Dear Customer Support Team,
I hope this message finds you well. I am writing to seek assistance regarding my recent order, #12345, placed on October 10, 2023.
Best regards,
Phoenix
Hi there,
It looks like our courier mixed up the order. Sorry about that!
Have requested the drop-off the correct item with you tomorrow.
Quick & Easy Setup
Get running in 3 easy steps
Share your details
Tell us about your domains, volume, and current sequencer. Two minutes, max. no demo call.
Configure your stack
Pick provider (Google / Microsoft / Azure / SMTP), set quantity. AI autofills personas, DNS pushes itself.
Go live with auto-warmup
Mailboxes provision in ~7 min, warmup auto-starts, one-click push to Instantly, Smartlead, or any sequencer.
Get started here
Comparison
We did the comparison table so you don't open six tabs.
How Purchasing Works
Buying is the easy part. On purpose.
Create your workspace
Free account, no card needed to look around.
Add domains
Buy in-app (we register + Cloudflare-manage them, you own them) or connect your own. DNS verifies automatically.
Configure your stack
Pick provider (Google / Microsoft / Azure / SMTP), set quantity, let AI autofill names and personas. Price per mailbox shows live.
Pay your way
Pay-as-you-go from your wallet, or a plan if you like predictable invoices. Monthly, quarterly, or yearly (yearly = 2 months free).
We provision
Mailboxes live in ~7 minutes, DNS pushed, warmup auto-starts. Pre-warmed boxes arrive ready to fire.
Export & send
One click into your sequencer. StackGuard watches your back from here.
Pricing
Pay only when you send.
Pay-as-you-go
No subscription. No commitment. Top up your wallet, spin up mailboxes, send. Done.
What's included
- Automated DKIM, SPF, DMARC setup
- Unlimited mailbox export
- Domain purchase or bring-your-own
- Cloudflare-managed DNS
- US/EU IP accounts exclusively
- Free unlimited mailbox replacement
- Live chat support, even weekends
- OAuth push to 50+ sequencers
Google Workspace
Microsoft 365All plans include
- Domain management
- Real-time mailbox creation
- Mailbox exports
- Unified inbox
Refund policy , short version: we're reasonable. Unused balance is refundable.
Wall of Love
People say nice things.
We screenshot them.
“We were losing two days a month to DNS. Switched to InboxStack. it's now a 7-minute task.”
“Their support replied on a Sunday at 11pm. I'm never going back to ticket-purgatory vendors.”
“Inbox placement jumped from 71% to 96% in two weeks. Same offer, same lists, same sequencer.”
“Scaled from 60 to 400 mailboxes across 14 client workspaces without a single deliverability fire.”
“We were losing two days a month to DNS. Switched to InboxStack. it's now a 7-minute task.”
“Their support replied on a Sunday at 11pm. I'm never going back to ticket-purgatory vendors.”
“Inbox placement jumped from 71% to 96% in two weeks. Same offer, same lists, same sequencer.”
“Scaled from 60 to 400 mailboxes across 14 client workspaces without a single deliverability fire.”
“Pre-warmed mailboxes saved us a launch. We were sending on day one, not week three.”
“The unified inbox alone is worth it. My reps stopped opening 30 Gmail tabs.”
“Banned mailbox replaced in 12 minutes, free. That's not customer service. that's infrastructure.”
“Cheapest infra we've used and somehow the most reliable. Make it make sense.”
“Pre-warmed mailboxes saved us a launch. We were sending on day one, not week three.”
“The unified inbox alone is worth it. My reps stopped opening 30 Gmail tabs.”
“Banned mailbox replaced in 12 minutes, free. That's not customer service. that's infrastructure.”
“Cheapest infra we've used and somehow the most reliable. Make it make sense.”
Api
Building an AI SDR?
Cool. Skip this website and hit the API.
Faq
Asked often. Answered honestly.
Infrastructure, not a sequencer. We set up and maintain the domains and mailboxes; your outreach tool does the sending. Think of us as the foundation under Instantly/Smartlead/ReachInbox.