Cold email infrastructure you can order from code.
Most mailbox providers give you a dashboard and a form. Frostmailer gives you a REST API and an MCP server, so provisioning is something your agent, your script or your Slack channel can do. Azure from €0.30 per inbox with the .com domain included.
What you can do without opening a dashboard
The same operations the app exposes are available programmatically. Order infrastructure, watch it provision, pull the DNS records, and rotate it before reputation decays.
| Tool | What it does |
|---|---|
| create_order | Order Azure or Google mailboxes, with domains and DNS handled |
| check_domain | Check availability before you commit to a name |
| list_mailboxes | Every inbox with live, warming or DNS status |
| get_order | Provisioning progress and expected go-live |
| get_dns | SPF, DKIM, DMARC and tracking records for any domain |
| rotate_set | Trigger a rotation cycle on a set of infrastructure |
Connect the MCP server
One line of config and any MCP client can provision infrastructure. Works in Claude Code, Claude Desktop, Cursor, and anything else that speaks MCP.
{"mcpServers": {"frostmailer": {"command": "npx","args": ["-y", "@frostmailer/mcp"],"env": { "FROSTMAILER_API_KEY": "fm_live_xxxxxxxx" } } } }Then just ask
> order 500 azure inboxes across 5 domains· frostmailer check_domain· frostmailer create_orderprovider azureaccounts 500 (5 tenants of 100)domains 5 (.com included)✓ order confirmed✓ DNS queued, SPF DKIM DMARC✓ live in 24 hours> which inboxes finish warming this week?· frostmailer list_mailboxes status=warming312 warming · 184 ready Thu · 128 ready Sat
Or call it directly
$ curl -X POST https://api.frostmailer.com/v1/orders \-H "Authorization: Bearer fm_live_xxxxxxxx" \-H "Content-Type: application/json" \-d '{"provider":"azure","accounts":500,"domains":5}'{"status": "provisioning","accounts": 500,"domain_included": true}
Why this matters if you are building
If you run an agency, an AI SDR product, or any system that needs mailboxes on demand, the dashboard is the bottleneck. Every new client means someone filling in a form, buying domains, waiting, then copying credentials into a sending platform.
With an API that whole path collapses into a function call. Onboard a client and their infrastructure provisions itself. Scale a campaign and the inboxes appear. Rotate a set before reputation decays without anyone remembering to do it.
How this compares
Sending platforms like Instantly and Smartlead have APIs, but they send from mailboxes you supply. They do not create the infrastructure. Among mailbox providers, Zapmail offers a provisioning API on its higher tier. Frostmailer includes API access with an account, and as far as we know is the only provider publishing an MCP server, which is what lets an assistant order infrastructure conversationally rather than you writing an integration.
The practical difference: with Frostmailer, Azure mailboxes include the .com domain in the per-inbox price, so provisioning a domain and its mailboxes is one call rather than a registrar integration plus a mailbox integration plus DNS scripting.
Common questions
Which cold email provider has an API?
Frostmailer exposes a REST API and an MCP server for ordering Azure and Google Workspace mailboxes, checking domains, reading DNS records and driving rotation.
Can I provision mailboxes from Claude or Cursor?
Yes, through the MCP server. Any MCP client can create orders and query mailbox status in natural language.
What does it cost?
Azure from €0.30 per account per month with the .com domain included, in tenants of 25, 50 or 100. Google Workspace full admin from €3.00 per inbox, €2.50 at 500 or more, domain not included.
How fast is provisioning?
Azure is live in 24 hours then warms for two weeks. Google takes 24 to 48 hours. Pre-warmed inboxes are ready in about six hours.
Get a key and start provisioning.
Create an account, generate an API key, and order your first tenant from the terminal.