InboxPlease for AI agents
By Chris Aylott, Founder
InboxPlease is an email deliverability platform that diagnoses why email lands in spam. Through its MCP server (Enterprise plan) or REST API (Pro and Enterprise plans), an AI agent can get a deliverability overview, read Domain Health, run inbox placement tests, analyse emails, and monitor or pause warmup. No tool browses or searches your inbox, and mailboxes connected through the standard InboxPlease app are send-only.
Set up the connection
Create an inp_ API key in the dashboard (Settings → API keys) and tick only the scopes the agent needs. New to InboxPlease? Run the free email test first.
MCP server
Add the server to Claude Code with the key in an Authorization header. Other MCP clients connect to the same https://api.inboxplease.com/mcp endpoint (MCP over Streamable HTTP). Details are on /features/mcp.
# Connect InboxPlease to Claude Code claude mcp add --transport http inboxplease \ https://api.inboxplease.com/mcp \ --header "Authorization: Bearer inp_YOUR_API_KEY"
REST API
Send the key in the X-API-Key header to any endpoint under https://api.inboxplease.com/api/v1/developer. GET /whoami returns the key's identity, organization, plan and scopes, so it is the quickest check that a key works. The endpoint list is on /features/rest-api.
# Who is this key? Returns organization, plan and scopes. curl https://api.inboxplease.com/api/v1/developer/whoami \ -H "X-API-Key: inp_YOUR_API_KEY"
Plans and limits
| Interface | Plan | Rate limit | Auth |
|---|---|---|---|
| MCP server | Enterprise (EUR 299/mo) | 300 requests/min and 10 concurrent calls per key | Authorization: Bearer, inp_ key with the /mcp/ scope |
| REST API | Pro (EUR 79/mo) and Enterprise | 60 requests/min per key, 1 MB max request body | X-API-Key header, inp_ key |
Access is gated by plan: the MCP server needs Enterprise, and the REST API needs Pro or Enterprise. REST access is checked against the plan on every call, so a downgrade removes it immediately. Free plans and expired trials have no API access.
What the tools do and do not do
The tools diagnose and monitor. No tool edits DNS or changes a domain's or mailbox's configuration; those changes stay with a person.
The only actions are pausing or resuming warmup, starting a placement test, returning an OAuth link for a person to connect a mailbox, with the opt-in send scope, sending email, and, with the opt-in read scope, marking, starring or moving a known message.
Tools by task
Every MCP tool, each listed once, with its exact name.
| Task | Tool | Access |
|---|---|---|
| Check which organization, plan and scopes a key has | whoami | Any MCP key |
| Check a domain: get the deliverability overview with recommendations | get_deliverability_overview | Feature scope |
| Check a domain: run a deliverability analysis | domain_analysis | Feature scope |
| Check a domain: read its latest Domain Health result | get_domain_health | Feature scope |
| List monitored domains and their latest health | list_health_domains | Feature scope |
| Read a domain's scan history | get_domain_scan_history | Feature scope |
| Read the result of one scan | get_domain_scan | Feature scope |
| Get a domain's full profile | domain_profile | Feature scope |
| Read reputation signals | reputation_scores | Feature scope |
| Get SEO/GEO metrics | seo_geo_analysis | Feature scope |
| Test inbox vs spam: start a placement test, manual or from a connected mailbox | start_placement_test | Action scope · owner/admin key |
| Test inbox vs spam: read inbox / tabs / spam per provider | get_placement_result | Feature scope |
| List placement tests | list_placement_tests | Feature scope |
| Analyse a raw email: authentication, sending IP, hops and content verdicts | analyze_email | Feature scope |
| Monitor warmup: list senders with status and inbox rate | list_warmups | Feature scope |
| Monitor warmup: read one sender's stats | get_warmup_stats | Feature scope |
| Pause a sender's warmup | pause_warmup | Action scope · owner/admin key |
| Resume a sender's warmup | resume_warmup | Action scope · owner/admin key |
| List connected mailboxes | list_mailboxes | Feature scope |
| Check a mailbox's connection status | check_mailbox_connection | Feature scope |
| Connect a mailbox: returns an OAuth link a person must open | connect_mailbox | Action scope · owner/admin key |
| Send email: see the remaining recipient budget | get_send_quota | Send scope |
| Send email: stage a preview (nothing is sent yet) | send_email | Send scope |
| Send email: confirm a previewed send | confirm_send | Send scope |
| Send email: check a send's outcome by its send_id, without sending again | get_send_status | Send scope |
| Campaigns: check that campaign sending is available for a sender | get_campaign_capabilities | Send scope |
| Campaigns: read recorded opens, clicks, replies and bounces for a send | get_send_engagement | Send scope |
| Read one known message by ID (mailboxes connected over IMAP only) | read_email | Read scope |
| Mark a known message as read | mark_email_read | Read scope |
| Star a known message | star_email | Read scope |
| Move a known message to inbox, sent, spam or important | move_email | Read scope |
Safety
A reference app built on it
Outreach Please is a reference outreach app built only on the public REST API and MCP server. Its server holds the inp_ key, stages every send with send_email and calls confirm_send only after a person approves the preview, and checks Domain Health before a campaign goes out, with an optional placement test. See how Outreach Please is built.
Start with the free email test
See how one of your emails authenticates and where it lands before you connect an agent.