INFRASTRUCTURE

We run 20,000+ inboxes. Most agencies run 400.

Cold outbound is a deliverability problem disguised as a copy problem. Everything on this page is the actual engineering work that sits under every campaign — domains, DNS, warmup, rotation, monitoring.

0
Active mailboxes
Across Microsoft + Google Workspace
0+
Secondary domains
Firewalling your primary
0%
Primary-inbox rate
Monitored daily via seed tests
99.0%
Uptime, 2025 YTD
SLA-monitored, alerted to Slack
THE SEND PATH

Every email passes through five layers.

Your primary domain never touches outbound. Ever. Here's what the actual send path looks like from the copywriter's keyboard to the prospect's inbox.

01 · YOUR PRIMARY DOMAIN
yourcompany.com
Never touches outbound.
02 · SECONDARY DOMAINS
yc-sales.com, yc-team.com, tryyourcompany.com…
3-5 per client. Bought fresh, separate registrar. SPF/DKIM/DMARC configured day one.
03 · WARMED MAILBOXES
70 dedicated per engagement
Split across Microsoft 365 + Google Workspace. 14-day warmup in our proprietary pool before a single cold email ships.
04 · SMARTLEAD ROTATION
Round-robin sender + pause rules
If any mailbox's reputation dips, it auto-pauses. The rest keep sending. No single sender carries the load.
05 · TARGET INBOX
87%+ primary placement
Monitored via GlockApps seed tests, weekly. Deliverability report shipped to your Slack.
The firewall principle

If a secondary domain's reputation ever takes damage — a competitor reports us, a typo sends the wrong ICP, a spam trap hits — your primary is insulated. We burn and replace secondaries as a cost of doing business. You never see it.

DNS STACK

Every record, configured day one.

The #1 deliverability killer we see when auditing other agencies is DNS hygiene. Missing DKIM. Permissive DMARC. SPF flattening failures. We ship every record below on every secondary domain, before a single mailbox warms.

  • Monitored daily with DMARC reports piped to Slack
  • Re-keyed DKIM on 12-month rotation
  • BIMI verified where clients supply a logo
  • SPF flattened when include count exceeds 8
dig yc-sales.com
SPF v=spf1 include:_spf.google.com include:sendgrid.net ~all
DKIM v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8A…
DMARCv=DMARC1; p=reject; rua=mailto:dmarc@yc-sales.com; aspf=s; adkim=s
MX 1 aspmx.l.google.com · 5 alt1.aspmx.l.google.com · 5 alt2.aspmx.l.google.com
CNAMEem.yc-sales.com → u12345.wl.sendgrid.net
BIMI v=BIMI1; l=https://yc-sales.com/bimi/logo.svg
;; Query time: 12 msec
;; STATUS: PASS · 6/6 records valid
THE STACK

27 vendors. One invoice.

SENDING
  • Microsoft 365
  • Google Workspace
  • SMTP (Azure)
  • SendGrid (warm IPs)
ORCHESTRATION
  • Smartlead
  • EmailBison
  • Instantly (backup)
ENRICHMENT
  • Clay (Elite partner)
  • Ocean.io
  • BuiltWith
  • Store Leads
  • Crunchbase
DATA & SIGNALS
  • LinkedIn Sales Navigator
  • GetSales
  • Triggr
  • Apollo (signal layer only)
CRM & REPORTING
  • Close
  • HubSpot
  • Salesforce (sync only)
MONITORING
  • GlockApps
  • MxToolbox
  • Postmark DMARC reports
  • Custom Slack alerts
INFRASTRUCTURE FAQ

Questions we actually get asked

Volume isn't the goal — survivability is. If any single mailbox or secondary domain takes reputational damage, the rest keep sending. A 200-mailbox setup with a bad week loses the whole month. A 20K-mailbox setup loses a rounding error.
Ready?

Your pipeline, rebuilt.

20-minute strategy call. We'll audit your ICP, show you which signals we'd track, and map out exactly what the first 120 days would look like. No commitment, no pressure, no pitch deck.

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Certified partnersClayEmailBisonCloseSmartleadHubSpot
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