Cold email inbox providers, compared

The same thirteen questions put to WarmInboxes and to each provider people compare us with. Our answers are checked against the published price list at build time. Theirs are filled only from their own pages, with the date, and say so until they are.

1. Price. What is the price per inbox per month, by platform and billing cycle, and what does a domain add?
2. Provider type. Are these official Google Workspace, Microsoft 365 or Azure accounts, or SMTP infrastructure of their own? Shared tenants or isolated?
3. Setup time. How long from payment to mailboxes you can send from, and does that include DNS?
4. Domain ownership. Who registers the domain, who owns it, and what happens to it if you cancel?
5. DNS setup. Are SPF, DKIM, DMARC and forwarding set before handover, and verified against a delivered message?
6. Warmup. Prewarmed, or warmed after purchase? For how long, by what method, and does it keep running?
7. API access. Is there a documented API to order, read build state and export mailboxes, with a sandbox?
8. MCP support. Can an AI assistant act on the account through an MCP server, and is the free diagnostic layer reachable without a key?
9. Sequencer integration. Which sequencers can mailboxes be exported into directly, and what does the export need?
10. Support. What channel, what hours, and who answers: operators or a ticket queue?
11. Replacement policy. What happens when an inbox stops landing: replaced, on what terms, in what time?
12. Testing methodology. Is placement testing published, with dates, senders, seed accounts and sample sizes?
13. Real observations. Does the provider send cold email on this infrastructure themselves, at what volume, and is any of it published?