Microsoft 365 mailboxes that actually work for cold email
Official M365 accounts with automated DKIM via Exchange Online, OAuth exports, and no 'Microsoft premium' pricing. The right tool when your list is full of Outlook inboxes.
ESP matching
Microsoft-to-Microsoft sends see better placement at Outlook. Split your fleet 50/50 against mixed lists and watch reply rates climb — same campaign, same copy, different sender.
The hard parts, automated
Exchange Online DKIM, tenant config, app passwords, OAuth, and the dance of getting M365 to talk cleanly to Smartlead or Instantly are notorious manual pain points. We handle all of it.
Stability
Many providers treat M365 as an unstable afterthought — user reviews of competitors say as much. Here it's a first-class product with the same uptime, monitoring, and replacement guarantees as Google Workspace.
Microsoft direct $6+/user, manual everything · InboxKit M365 surcharged · CLAYINBOX $2.50 flat
Common questions
More from the platform
Real Workspace accounts with full admin access, automated DNS, isolated one-domain workspaces, and free warmup — at less than a third of Google's retail price.
Dedicated Azure tenant per domain with up to 100 mailboxes — $0.25 effective per mailbox at full density. Built for high-volume senders who understand the trade-offs.
Export pipeline pushes mailbox credentials and tracking domains to your sequencer via API — not CSV. Auto-reconnect when credentials rotate.