Email Connectors API

Overview & Authentication

A standalone service to connect an email account, send, and receive across three providers. The three connectors share one API — your app always calls the same /send and /fetch; only the one-time connect step differs per provider (imap_smtp, outlook, or google).

Last updated: 2026-08-08

Response format & status codes

{
  "success": true,
  "data": { }
}

{
  "success": false,
  "error": {
    "code": "STRING",
    "message": "..."
  }
}

Health (no auth)

curl https://api.reinterface.com/healthz

{"status":"ok"}

Common account endpoints

Account operations work for all providers. Responses show provider and conn_status; passwords and tokens are never returned.

List all accounts

curl https://api.reinterface.com/api/v1/accounts \
  -H "x-api-key: <API_KEY>"

Get one account

curl https://api.reinterface.com/api/v1/accounts/USER@DOMAIN.com \
  -H "x-api-key: <API_KEY>"

Delete an account

curl -X DELETE https://api.reinterface.com/api/v1/accounts/USER@DOMAIN.com \
  -H "x-api-key: <API_KEY>"

Unified send — POST /send

Works for all providers. The service auto-selects SMTP, Microsoft Graph, or Gmail API from the connected from account.

curl -X POST https://api.reinterface.com/api/v1/send \
  -H "x-api-key: <API_KEY>" \
  -H "content-type: application/json" \
  -d '{
    "from": "USER@DOMAIN.com",
    "to": "recipient@example.com",
    "subject": "Hello",
    "html": "<p>Body</p>"
  }'

{
  "success": true,
  "data": {
    "messageId": "<...>",
    "accepted": ["recipient@example.com"],
    "rejected": null
  }
}

Unified fetch — POST /fetch

Searches Inbox + Spam/Junk; returns placement + SPF/DKIM/DMARC. Match by messageId (exact, preferred) or subject (substring).

curl -X POST https://api.reinterface.com/api/v1/fetch \
  -H "x-api-key: <API_KEY>" \
  -H "content-type: application/json" \
  -d '{
    "email": "USER@DOMAIN.com",
    "subject": "Hello"
  }'

curl -X POST https://api.reinterface.com/api/v1/fetch \
  -H "x-api-key: <API_KEY>" \
  -H "content-type: application/json" \
  -d '{
    "email": "USER@DOMAIN.com",
    "messageId": "<abc@sender.com>"
  }'

{
  "success": true,
  "data": {
    "count": 1,
    "emails": [
      {
        "messageId": "abc@sender.com",
        "subject": "Hello",
        "from": "sender@example.com",
        "to": "USER@DOMAIN.com",
        "date": "2026-07-02T08:00:00Z",
        "folder": "inbox",
        "receivingIp": "1.2.3.4",
        "spf": "pass",
        "dkim": "pass",
        "dmarc": "pass",
        "rawHeaders": "..."
      }
    ]
  }
}

Not found: { "success": true, "data": { "count": 0, "emails": null } }. Errors: 404 (account not connected), 502 (fetch failed). After /send, delivery can take a few seconds — poll /fetch until count > 0.

folder values: inbox, spam, trash. SPF/DKIM/DMARC may be pass, fail, softfail, neutral, or unknown.

Connector A — IMAP / SMTP Working

Standard mailboxes (host + port + user + password). No OAuth. Connect validates IMAP + SMTP, then stores; passwords encrypted at rest.

Connect

curl -X POST https://api.reinterface.com/api/v1/accounts \
  -H "x-api-key: <API_KEY>" \
  -H "content-type: application/json" \
  -d '{
    "email": "USER@DOMAIN.com",
    "imap_host": "imap.domain.com",
    "imap_port": 993,
    "imap_username": "USER@DOMAIN.com",
    "imap_password": "secret",
    "smtp_host": "smtp.domain.com",
    "smtp_port": 587,
    "smtp_username": "USER@DOMAIN.com",
    "smtp_password": "secret"
  }'

→ 200 with the stored account (conn_status: "valid"); or 400 IMAP_FAILED / SMTP_FAILED.

Validate without storing

POST /api/v1/accounts/test-imap with host, port, username, password. Same shape for POST /api/v1/accounts/test-smtp. Then use unified /send and /fetch.

curl -X POST https://api.reinterface.com/api/v1/accounts/test-imap \
  -H "x-api-key: <API_KEY>" \
  -H "content-type: application/json" \
  -d '{
    "host": "imap.domain.com",
    "port": 993,
    "username": "USER@DOMAIN.com",
    "password": "secret"
  }'

curl -X POST https://api.reinterface.com/api/v1/accounts/test-smtp \
  -H "x-api-key: <API_KEY>" \
  -H "content-type: application/json" \
  -d '{
    "host": "smtp.domain.com",
    "port": 587,
    "username": "USER@DOMAIN.com",
    "password": "secret"
  }'

Connector B — Outlook (OAuth / Microsoft Graph) Needs Azure admin consent

For Microsoft 365 / Outlook mailboxes.

One-time Azure setup

• App Reinterface (client 02e56072-0f37-4467-b088-c356ce7b46b6).
• Add redirect URI (App registration → Authentication → Web): https://api.reinterface.com/api/v1/oauth/outlook/callback
• Mailbox must be in a tenant the app allows; tenant admin may need to Grant admin consent once.

Connect

Request the consent URL with your API key, then open it in a browser:

curl "https://api.reinterface.com/api/v1/oauth/outlook/authorize?email=USER@DOMAIN.com&format=json" \
  -H "x-api-key: <API_KEY>"
# → {"authUrl": "https://login.microsoftonline.com/...", "email": "USER@DOMAIN.com"}
# Open authUrl in the browser.

→ sign in → consent → "Outlook account connected". Then use unified /send and /fetch.

Connector C — Google (OAuth / Gmail API) Ready

For Gmail / Google Workspace mailboxes.

One-time Google Cloud setup

• OAuth client 443730906966-a8vahhuan2mi86jlmr5dh3c8u64fesig.apps.googleusercontent.com (project 443730906966).
• Redirect URI (already registered): https://api.reinterface.com/api/v1/oauth/google/callback
• Scopes: gmail.send + gmail.readonly (restricted) and calendar.events + calendar.readonly (sensitive), plus openid email profile.
• Publishing status: "In production" = any user; "Testing" = test users only, refresh token expires in 7 days.

Connect

Request the consent URL with your API key, then open it in a browser:

curl "https://api.reinterface.com/api/v1/oauth/google/authorize?email=USER@gmail.com&format=json" \
  -H "x-api-key: <API_KEY>"
# → {"authUrl": "https://accounts.google.com/o/oauth2/...", "email": "USER@gmail.com"}
# Open authUrl in the browser.

→ sign in → consent → "Google account connected". Then use unified /send and /fetch.

Gmail & Calendar APIs

Operating on a connected Google account — sending Gmail, reading messages, and managing Calendar events — is its own surface, authenticated with your personal API key from the dashboard Settings page. It is documented separately: Gmail API reference and Calendar API reference.

Full endpoint summary

Service surface — x-api-key:

Notes

• One API, three providers — connect differs; /send and /fetch are identical.
• Credentials at rest: IMAP/SMTP passwords and OAuth refresh tokens are AES-256-GCM encrypted; access tokens fetched on demand, never stored; secrets never returned.
• Max request body: 25 MB.
• SPF/DKIM/DMARC come from the receiving server's Authentication-Results header; they read unknown only for internal-only deliveries that omit that header.
• API keys go in the x-api-key header only; the API does not accept keys in URLs.