Workflow · Email + LinkedIn infrastructure

Cold email that actually lands.

Domain procurement, DNS, inbox warmup, deliverability monitoring, LinkedIn outreach automation. All infra owned and operated by us.

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The bottleneck

47% of cold email hits spam. The fix isn't a better subject line.

47%
Of cold outbound emails route to spam at the gateway
21 days
Minimum warmup runway for a new domain to land in primary
$2.8K
Monthly cost of a real sending stack — domains, mailboxes, tooling

Deliverability is an infrastructure problem, not a copywriting problem. Most teams discover this six weeks in, after a cold sequence burned a domain and the founder's inbox started showing up in spam folders. The fix is a stack — aged domains, clean DNS, warmed mailboxes, monitored reputation, rotation policies, LinkedIn accounts paired carefully. We own the whole thing so your team never has to learn what an SPF record is.

How we work

Four weeks. Ready to send.

  1. Week 01

    Domains land.

    Shortlist approved by you. Aged-domain sourcing or fresh registrations under your brand, diversified across TLDs. Registrations live, DNS records propagated, MX wired to the sending platform — verified across Gmail, Outlook, and Workspace.

  2. Week 02

    Warmup begins.

    Inboxes provisioned, mailboxes seeded, warmup tools running. First conversational simulation cycles live. Reputation graphs tracked daily and surfaced in your Slack — any flagged domains rotated out before they burn.

  3. Week 03

    Volume ramps.

    Sending volume increases gradually across the pool. Inbox-placement tests across providers weekly. LinkedIn accounts paired and warmed through manual activity in parallel — IPs rotated, daily limits respected, zero banned accounts.

  4. Week 04

    Ready to send.

    Full inbox health report delivered. Sequencing tool wired into your CRM. First cold sends graduated from the warmup pool — monitored daily, with replies threaded into a single inbox and routed to your Slack.

In production

How it looks in production.

Case 01 · Series B SaaS scaling outbound to 50k contacts/month

32 domains, 96 inboxes, zero burned in 90 days.

Problem.

Existing setup: 8 domains, 24 inboxes, primary-tab placement collapsing below 60%. Reply rates falling, deliverability blocklists creeping in, primary sending domain at risk. Sales team blaming product; product team blaming sales.

What we did.

Fresh sending stack stood up parallel to the existing one. 32 separate sending domains registered and warmed for three weeks. 96 inboxes across them, three per domain, each sending 30/day. SPF/DKIM/DMARC tuned. Migration cut over inboxes over six weeks while we monitored deliverability per inbox in real time.

98%+
Primary-tab placement · 90 days
0
Inboxes burned
“We went from worrying about deliverability every Monday to not thinking about it at all.”— Head of Growth
Case 02 · Seed-stage AI company recovering from a domain burn

Primary domain off the Spamhaus list in 17 days.

Problem.

Founder had been running outbound from their primary @company.com sending alias. Volume crept up, complaint rate spiked, Spamhaus blocked the root domain. Inbound demo requests stopped landing. Investors couldn't reach the team.

What we did.

Hard cut over to a separate sending estate within 48 hours. Three new domains registered, parked-then-warmed in parallel. Worked the appeal queue at Spamhaus with documented complaint-handling. Cleaned the original list, killed the worst-performing segments, restored sending discipline.

17 days
Time to delist
0
Days primary email was actually broken
“They moved faster than the team that caused the problem in the first place.”— Founder & CEO
Case 03 · Agency standing up outbound for 14 clients

From spreadsheet chaos to one source of truth.

Problem.

Outbound agency running 14 active clients across as many sending stacks. No central monitoring. Inboxes randomly cooling off. Clients churning when deliverability dipped — by the time the agency noticed, it was already a fire.

What we did.

Centralized sending estate with per-client domain isolation. 84 inboxes across 28 domains, mapped to clients. Real-time bounce, complaint, and reply monitoring in a shared dashboard. Per-client warmup playbooks codified. Account-level Slack alerts when any client's deliverability score dropped.

14 → 22
Client roster · 9 months
<2%
Bounce rate, all clients
“We finally have a sending stack we can actually scale on. Onboarding a new client is now a one-day job.”— Agency Founder
Free calculators

Plug in your numbers — do the math.

Calculator

Email inbox calculator

How many inboxes and domains you need for your target reply volume. Built on the same constraints that drive real sending estates.

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Calculator

Multi-channel calculator

Plan email + LinkedIn outreach together. See the combined footprint required for your meeting target.

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Knowledge base · 14 guides

Read the email infrastructure playbook.

Start here5 min

Complete email infrastructure setup

The full 14-guide walkthrough. SPF, DKIM, DMARC, MTA-STS, BIMI, ARC, subdomain isolation, warmup, bulk-sender compliance, monitoring, and reply detection.

Read the guide
Operations12 min

Inbox warmup, demystified

Why 2-3 weeks isn't optional. Engagement curves, the ramp methodology, and why volume-based synthetic warmup is now detected at major receivers.

Read the guide
Architecture13 min

Subdomain isolation — the reputation firewall

Why founders should never run cold outbound from their corporate domain. The 32-domain math for a 30-rep team, and the lookalike domain pattern.

Read the guide
Browse all 74 guides in the knowledge base →
Frequently asked

Common questions.

How fast can you start?
Forty-eight hours from Slack invite to first domains on the registrar. First mailboxes live by end of week one. Full sending stack at 28 days.
Do I keep the domains and inboxes if we stop working together?
Yes. Everything is registered under your entity, billed to your card, on your provider accounts. We don't run anything through our infrastructure — the engineer leaves your Slack, your stack stays yours.
What sending platform do you use?
We're platform-agnostic. Smartlead, Instantly, Apollo, Outreach, Salesloft — whatever fits your motion. If you're already on one, we slot in. If not, we'll recommend based on volume and ICP.
Will my LinkedIn accounts get banned?
Not in any production deployment we've run. We use multi-account architecture, IP rotation, conservative daily limits, and manual warmup. The accounts that get banned are the ones running 80 connects a day on day one.
How much does this cost the company per month?
Custom per workflow — book a call to scope. The infrastructure itself (domains, mailboxes, warmup, sequencing tool) is between $1,500 and $4,000/mo depending on volume. Our engineering fee is on top.
Are you an agency?
No. We're an engineering team. The person in your Slack writes code, owns the deliverability dashboard, and is on call when a domain starts showing up on a blocklist.
Let's talk

Need inboxes by next month?

Sending infrastructure provisioned, warmed, and ready in four weeks. No tools to buy. No SDR to hire. We own the stack.

Talk to us today →
Or email phillip@allstonlabs.com