Google & Microsoft Infrastructure Built Different
Mailboxes Built to
Upgrade Your Reply Rates
Upgrade your performance — premium warmup included, ready in minutes, API-powered, and flexibly billed so you only pay for what you use.
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Domain Manager
3 active · 2 uploadingDomainESPReputationStatus
outreach-hq.io
→ milkboxhq.com
99%
Active
salesdev.co
→ milkboxhq.com
98%
Active
b2b-reach.net
→ milkboxhq.com
—
Uploading
growth-engine.io
→ milkboxhq.com
100%
Active
coldpro.co
→ milkboxhq.com
—
Canceled
outbound-x.co
→ milkboxhq.com
—
Uploading
Active
3
Uploading
2
Avg Rep.
99%
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MilkBox
MilkBox
How It Works
Up and Running in 4 Steps
Step 1
Buy your slots
Sign up in under a minute and buy as many mailbox and domain slots as you need — no rigid packages. Not sure how many? Use our Mailbox Calculator to estimate.
Domain Provider Integrations
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porkbunporkbunporkbunSequencer Integrations
The Problem — and the Fix
Your provider optimizes for their margins, not your reply rates.
The Problem
MilkBox Fix
Rigid packages force you to overbuy — need 7 domains? Buy 10
Slot billing — pay for exactly what you use · one invoice per month
Campaign copy warmup? Not on their roadmap
Warm up with your actual campaign copy — only provider doing this
Premium warmup costs $25–100/month extra
Premium warmup included — no extra charge
Warmup pools diluted with SMTP accounts ESPs ignore
100% Microsoft & Google professional accounts — zero SMTP in the pool
No visibility into domain health or inbox placement
Real-time domain reputation + inbox placement tests built in
Manual DNS setup wastes hours per domain batch
Fully automated NS, DNS, SPF, DKIM, DMARC — set up in minutes
How We Compare
Sending Provider Performance
Not all infrastructure is equal. Here's how MilkBox stacks up on the features that actually move reply rates.
| Feature | MilkBoxOur platform | Typical Provider |
|---|---|---|
Premium WarmupKey | Included | Not offered, or a paid add-on |
Warmup PoolKey | Microsoft 365 & Google Workspace only | Heavy on SMTP accounts |
Reply Routing After Cancellation | Late replies to cancelled domains forwarded to your inbox | |
Domain Swaps | Easy, anytime | Harder, often through support |
Billing | One monthly bill per slot | A separate subscription per order, each renewing on its own date |
* "Typical Provider" represents common practice in the cold email mailbox market, not a specific company.
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Warmup features built for real campaigns
With MilkBox you have complete warmup control.
Warmup Distribution
emailsleadconversion.com100%allocated
Google Workspace
14%
Gmail
17%
Microsoft 365
15%
Outlook
26%
Yahoo
6%
Custom SMTP
22%
6 providers configured
Per-domain config
Warmup Distribution
Control where warmup emails go
- Set exact % split between Gmail, Outlook, Yahoo, and more
- Mirror real-world recipient distribution for your niche
- Configure per-domain for maximum accuracy
- Supports MS365, Google Workspace, SMTP, and custom
Copy Warm-Up
Warmup with your actual copy
- Upload HTML or plain-text templates from your real sequences
- Warmup simulates your actual campaign — not lorem ipsum
- Reduces spam flagging that kills copy after 2 weeks
- Assign specific templates per domain
- Premium warmup included in all plans — other providers charge $25–100/month extra
Warm-Up Manager
5 active · 0 inactiveStatusNameAssignedSentDeliverability
Active
Outreach v1 — EMEA
3
1,240
98%
Active
Outreach v2 — LATAM
5
2,890
97%
Active
Outreach v3 — APAC
2
847
99%
Active
Nurture v1 — EMEA
4
1,560
100%
Active
Followup v1 — NA
1
312
97%
Active
5
Inactive
0
Avg Deliverability
98%
Powered by
MilkBox
MilkBox
Running Spam Test…
outreach-hq.io—
ProviderInboxSpam
Google Workspace
—
—
Gmail
—
—
Microsoft 365
—
—
Outlook
—
—
Yahoo
—
—
Custom SMTP
—
—
Inbox
—
Spam
—
Inbox Rate
—
Powered by
MilkBox
MilkBox
Inbox Placement Test
Know your inbox rate before you send
- Test across 6+ providers: Google, Outlook, Yahoo, SMTP, and more
- Results: Inbox / Spam per provider — instant breakdown
- Full history of runs to track reputation over time
- 2 free tests per day, per domain — zero extra cost
Pricing
Transparent Pricing. No Hidden Fees.
Everything Included
Premium Warm-Up
Free & Unlimited Spam Tests
Campaign Copy Warm-Up
Full Tenant Isolation
30-90 Minutes
Premium Slack Support
Full API Access
Easy Domain Swap & Deletion
100% Automated Setup
API Integration with Sequencers & Domain Providers
★ Most Popular
No setup fees. No contracts. Add or remove slots anytime.
Premium Warmup included in every plan — other providers charge $25–100/month extra for the same.
Customer Stories
Real People. Real Results.
Don't just take our word for it. See what top-performing agencies and sales teams have to say.
"We were stuck at 2% replies and zero positive responses after sending to 600+ prospects with Instantly inboxes. MilkBox's infrastructure change was immediate - we hit 10.6% reply rates and generated 12 interested leads from our first 874 contacts. That's one positive reply per 73 sends versus... literally nothing before. The issue wasn't our offer - it was our email infrastructure."
Colin Dowling
Founder
Raincloud
"Milkbox has given us the confidence to tell our startups they're using the best-in-class email infrastructure, managed by an exceptional team. Since building our systems in-house with Milkbox, email has become a core driver of every outbound program."
Luke Bivens
Founder
QC Growth
"Almost a year using MilkBox and our performance has never been better. Our campaigns regularly hit over 10% reply rates. Even on Fortune 1000 targets, we're still pulling 3% replies — which is brilliant. They always outperform our other providers. It feels incredible to have such a great team taking care of our mailboxes and taking that off my mind."
Ben Robinson
Managing Director
Playbook Systems
"We were client #1 when MilkBox launched. No case studies, no proof, just Lucas promising performance. Now? We run monthly comparisons across all providers and MilkBox regularly outperforms by 2-3x. Best gamble we ever made."
Bobby Offterdinger
Founder & CEO
TAM To Target
"Been with MilkBox for over a year now—they're our only provider at this point. Regularly hit up to 9% reply rates on cold lists and 40-75% on event follow-up campaigns. Their support is great, delivery is extremely fast, and the infrastructure handles it all without issues. It just works!"
Karolis Zemaitis
Co-Founder
GrowTech
FAQ
Frequently Asked Questions
Everything you need to know about MilkBox
Warmup
Pricing & Plans
Setup & Infrastructure