US-based Microsoft tenants. DNS fully configured. Connected directly into your Instantly account. Launch-ready in 24-48 hours. Add our deliverability guarantee and if it doesn't perform, we refund 50%.
Powering outbound for cold email operators sending at scale
You buy inboxes from a reseller. You get SMTP credentials in a spreadsheet. You spend two hours configuring DNS yourself. Half the records are wrong. You fix them. You start warmup. A week later you launch and half your emails land in spam.
You reach out to support. They take 48 hours to reply. They tell you deliverability is your responsibility. You eat the cost. You find another provider. Same thing happens again.
The problem isn't your copy. It's not your sending tool. It's that your inbox provider has zero stake in whether your campaigns actually work.
We built NorthHorizonMails to fix that.
Not shared tenants. Not recycled IPs. Every domain gets its own dedicated US-based Microsoft 365 tenant running on Azure infrastructure. Bulletproof IP reputation from day one.
SPF. DKIM. DMARC. All configured before your inboxes reach you. You don't touch a single DNS record. We handle it because one wrong record kills deliverability and we don't leave that to chance.
We don't send you credentials and say good luck. We connect every inbox directly into your Instantly or Plusvibe account. You open your sending tool and your inboxes are there, ready to warm up. No manual imports. No SMTP headaches. Contact us if you need setup for other platforms.
Domain gets burned? We replace it. No extra charge. No questions. Operators scale aggressively and we built our system to handle that reality.
Need stronger domain quality from day one? We help you source 10+ year aged domains with a 10+ infrastructure score, giving you a cleaner foundation for deliverability.
Instantly, Smartlead, Salesforge, or any SMTP-compatible platform. White-glove setup is available for Instantly and Plusvibe. Contact us to add other tools.
Follow our system. Verified domains, 2-week warmup, recommended sending limits, clean copy. If deliverability still doesn't perform, we refund 50% of your domain costs. No other provider offers this. We do because we trust our infrastructure.
Not every campaign needs 99 inboxes. Choose 25, 49, 74, or 99 mailboxes/domain based on your volume needs. Scale up or down as your campaigns evolve.
Scaling volume? For every 11 domains you buy, we add 1 more at no extra cost. Simple pricing for operators growing fast.
Choose Normal, Premium, or Mixed. Select how many domains you need and how many mailboxes/domain (25, 49, 74, or 99).
We provision individual US Microsoft tenants, configure all DNS authentication, and connect your inboxes directly into your Instantly or Plusvibe account. You do nothing.
Your inboxes warm for 7 days using recommended settings. Domains build sender reputation the right way. No shortcuts, no tricks.
You're live. Fully configured Outlook inboxes. Bulletproof Microsoft Azure infrastructure. Sending from primary, not promo, not spam.
Most operators order on Monday and are warming up by Wednesday. By week 2, campaigns are live and landing replies. If you add the Deliverability Guarantee, warmup extends to 2 weeks with launch in week 3 instead of week 2 to ensure maximum inbox placement.
Complete setup included. DNS, authentication, Instantly or Plusvibe connection. Every plan. Every domain. Choose 25, 49, 74, or 99 mailboxes/domain.
Normal License
$45
100% Normal licenses
per domain every 4 weeks
Mixed License
$55
50% Normal + 50% Premium licenses
per domain every 4 weeks
Premium License
$65
100% Premium licenses
per domain every 4 weeks
Running at scale? Every 11 domains you purchase comes with a free one. Simple volume reward for operators scaling up.
Add to any plan. Requires 2-week warmup (launch in week 3 instead of week 2). If deliverability doesn't perform after following our system, we refund 50% of your domain costs. Full details →
Scroll horizontally to see full table →
| Normal ($45/mo) | Premium ($65/mo) | |
|---|---|---|
| Mailbox options | 25, 49, 74, or 99 | 25, 49, 74, or 99 |
| Cost per inbox (at 99) | ~$0.45 | ~$0.66 |
| Cold sends per inbox/day | 3–5 | 8–10 |
| Warmup time | 3–5 days | 3–5 days |
| Deliverability | Good | Excellent |
| Spam filter intelligence | High | Highest (strictest) |
| Infrastructure | Microsoft Azure | Microsoft Azure (higher-tier) |
| IP Reputation | Bulletproof | Bulletproof |
| IP Pool Quality | Standard | Cleaner, less saturated by cold emailers |
| Best for | Budget volume plays | Trusted high-value sends |
Go Premium if…
Sending to mid-market or enterprise ICPs where reply quality matters? Go Premium. The infrastructure is a different, higher-quality Microsoft license that most cold emailers don't use, which means you're sending from cleaner IP pools with less spam history. Your emails land where they should.
Go Normal if…
Running broad volume campaigns where cost per lead is king? Go Normal. Same bulletproof Azure infrastructure, same DNS setup, same support.
Go Mixed if…
Want both in one domain? Go Mixed.
Add the Deliverability Guarantee to any plan for $10/domain every 4 weeks.
Every inbox provider tells you their infrastructure is solid. We're the only one that puts money behind it.
The conditions are straightforward:
Follow every step. If deliverability still doesn't perform, we refund 50% of your domain costs.
Individual US-based Microsoft tenants. Azure infrastructure. Bulletproof IP reputation. SPF, DKIM, DMARC configured by us. We control the setup end-to-end, so we stand behind it end-to-end.
The guarantee requires a 2-week warmup instead of the standard 1 week. This extra week ensures your domains build maximum sender reputation before you launch. You go live in week 3 instead of week 2.
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Premium Outlook inboxes. White-glove setup. The only provider willing to refund you if deliverability doesn't perform.
Get Started24-48 hour setupNo contractsCancel anytime