Hypertide

Hypertide provides cold email inboxes on Google Workspace and on Microsoft Entra, also known as Azure. Tenant separation means every domain and IP is unique to you, which limits the risk of other senders affecting your reputation.

You can buy domains through Hypertide or bring your own, and enterprise-grade DNS is pre-configured on every account. Setup is fully automated and takes four to six hours. Hypertide says its Entra inboxes give a native Outlook experience, unlike other Azure resellers, and it connects to Smartlead, Instantly and EmailBison by OAuth or SMTP upload.

There are no packages or minimums and billing is month to month, so you can test without a long commitment.

Because each domain and IP is isolated, a deliverability problem on one domain is less likely to spill over to the others, which matters for agencies running campaigns for several clients at once.

Google Workspace inboxes cost $3.30 each a month, and Entra costs $25 per domain a month with 25 inboxes included. There is no free trial.