US-based Microsoft tenants. DNS fully configured. Connected directly into your Instantly account. Launch-ready within 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.
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.
Tenants provisioned, DNS configured, inboxes connected within 48 hours. You order, we build, you warm up.
Domain gets burned? We replace it. No extra charge. No questions. Operators scale aggressively and we built our system to handle that reality.
Instantly, Smartlead, Salesforge, or any SMTP-compatible platform. White-glove setup is available for Instantly and Plusvibe. Contact us to add other tools.
Set real profile pictures on every mailbox. Emails with profile photos look human and build trust. Higher open rates and reply rates.
Access your mailboxes to reply directly from the inbox. Useful when earlier conversations aren't accessible in your email outreach software.
Follow our system. Verified domains, 2-week warmup, week-3-only guarantee window, recommended sending limits, clean copy. Available on orders of 6 or more domains. If deliverability still doesn't perform in week 3, request your refund that week and we refund 50% of the subscription fees we charged.
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. Without the guarantee, campaigns are live in week 2. If you add the Deliverability Guarantee, warmup extends to 2 full weeks, launch happens in week 3, and the refund window applies only during that week.
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. Available on orders of 6 or more domains. Requires a full 2-week warmup, applies only during week 3, and refund requests must be submitted in week 3 after all criteria are met. 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 a one-time $5/domain. Available on orders of 6 or more domains.
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 does not perform during week 3, submit your request that same week and we refund 50% of the subscription fees we charged.
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. You launch in week 3, the guarantee applies only during that week, and refund requests must be submitted in week 3 after all criteria are met.
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Premium Outlook inboxes. White-glove setup. The only provider willing to refund you if deliverability doesn't perform.
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