Receive · Send · Organize
Build your own email
One API to receive, send and organize mail in Gmail, Outlook and IMAP. And a mail client you rebuild with Claude Code.
Connect your first mailbox in a minute.
curl https://gateway.supermail.best/rpc \
-H "Authorization: Bearer $SUPERMAIL_TOKEN" \
-d '{"jsonrpc":"2.0","id":1,
"method":"Events/list",
"params":{"account_id":"account_01H9X",
"types":["email.*"]}}'Event streamlive
account_01H9X · gmail
- email.updatedlabels +Important
- email.receivedInvoice #2041 · billing@acme.io
Works with the mail you already have and the agents you already use.
- Gmail
- Outlook
- IMAP
- Claude Code
- Codex
- Cursor
[ Your client ]
The inbox is yours to rebuild
The default client is just a starting point.
- 01Connect your mailGmail, Outlook or any IMAP account. Your address, your history.
- 02Describe your inboxTell Claude Code what your mail client should look like and do.
- 03Install itLoad your build from a manifest. Switch back to the default any time.
> build me an inbox that only shows people,
puts newsletters into a sunday digest
and drafts replies in my tone
✓ 41 files on the Supermail inbox API
✓ manifest.json written[ API ]
One API for all of email
Receiving was the hard part. Sending and organizing come with it.
Connect any mailbox
accounts ├─ account_01H9X gmail ACTIVE ├─ account_01HA2 outlook ACTIVE └─ account_01HB7 imap SYNCING
[ Agents ]
Hand your inbox to your agent
One MCP endpoint, one access key.
# Create an inbox access key in Settings → Connect AI agents
claude mcp add --transport http --scope user supermail \
"https://inbox.supermail.best/api/mcp" \
--header "Authorization: Bearer <wbi_key>"[ Use cases ]
Use cases
From support triage to a mail client nobody else has.
- make me an inbox that only shows people, no newslettersyou
- built 41 files on the inbox APIclaude code
- installed from manifestyou
- your client is live on your mailsupermail
[ By the numbers ]
Built by the people using it.
500+
Custom clients
People who already built their own mail client on Supermail.
1
API for all of email
Receive, send and organize across Gmail, Outlook and IMAP.
0
Lines of IMAP or SMTP
You never touch IMAP, SMTP, Gmail or Microsoft Graph.