The Shift in Cold Email Deliverability Algorithms
In 2026, mailbox providers like Google Workspace and Microsoft 365 have implemented sophisticated heuristic filters that look far beyond simple SPF and DKIM pass rates. They actively monitor IP cluster consistency, tenant history, reverse DNS resolution, and sending velocity.
Shared Resellers vs. Dedicated Azure Infrastructure
| Feature | Shared Resellers (Mailforge, Inframail) | Dedicated Azure via Heyo Infra |
|---|---|---|
| Cost Model | $3.00 - $5.00 / month / inbox | $0.25 / 1,000 sends wholesale (Azure) |
| Infrastructure Ownership | Third-party reseller tenant | 100% Owned in your Microsoft Azure Account |
| Reputation Isolation | Shared IP pools / pooled subnets | Isolated enterprise Azure tenant |
| Sender Compatibility | Proprietary UI or basic SMTP | Universal: Heyo Email, Instantly, Smartlead, Apollo |
How Dedicated Ownership Protects Your Brand
When you own your sending infrastructure directly inside Microsoft Azure, you are immune to sudden platform-wide reseller suspensions. If a reseller loses their upstream distributor agreement, thousands of customer inboxes go dark overnight. With Heyo Infra, your assets reside permanently within your own Microsoft organization.