@piyapat/office365-mcp-server

MCP server for Microsoft Office 365 email — create drafts and send email (with file attachments) via Microsoft Graph API. Email deletion is intentionally blocked.

Note: This package was previously published as office365-mcp-server and has been renamed to @piyapat/office365-mcp-server.

Tools

| Tool | Description | |---|---| | draft_email | Create a draft email (saved, not sent) | | send_email | Send an email immediately | | send_draft | Send an existing draft by message ID | | list_drafts | List drafts in the Drafts folder | | delete_email | BLOCKED — always returns an error |

Prerequisites

1. An Azure AD App Registration with:

   • Application permission: Mail.Send, Mail.ReadWrite
   • Admin consent granted for the tenant

2. Node.js 18+

Azure AD App Registration

1. Go to Azure Portal → Azure Active Directory → App registrations → New registration
2. Note the Application (client) ID and Directory (tenant) ID
3. Certificates & secrets → New client secret → copy the value
4. API permissions → Add Microsoft Graph application permissions:
   • Mail.Send
   • Mail.ReadWrite
5. Grant admin consent

Usage with npx (recommended)

1. Build locally (or publish to npm)

npm install
npm run build

2. Set environment variables

export AZURE_TENANT_ID="your-tenant-id"
export AZURE_CLIENT_ID="your-client-id"
export AZURE_CLIENT_SECRET="your-client-secret"

3. Run with npx

npx @piyapat/office365-mcp-server

Or run directly:

node dist/index.js

Claude Desktop / Claude Code configuration

Add to your claude_desktop_config.json or .claude/mcp.json:

{
  "mcpServers": {
    "office365": {
      "command": "npx",
      "args": ["@piyapat/office365-mcp-server"],
      "env": {
        "AZURE_TENANT_ID": "your-tenant-id",
        "AZURE_CLIENT_ID": "your-client-id",
        "AZURE_CLIENT_SECRET": "your-client-secret"
      }
    }
  }
}

Or if running from a local build:

{
  "mcpServers": {
    "office365": {
      "command": "node",
      "args": ["C:/Works/LLM/office365-mcp-server/dist/index.js"],
      "env": {
        "AZURE_TENANT_ID": "your-tenant-id",
        "AZURE_CLIENT_ID": "your-client-id",
        "AZURE_CLIENT_SECRET": "your-client-secret"
      }
    }
  }
}

Tool reference

draft_email

| Parameter | Type | Required | Description | |---|---|---|---| | userEmail | string | yes | Sender's O365 mailbox | | subject | string | yes | Subject line | | body | string | yes | Body content | | toRecipients | [{address, name?}] | yes | To recipients | | ccRecipients | [{address, name?}] | no | CC recipients | | bccRecipients | [{address, name?}] | no | BCC recipients | | isHtml | boolean | no | Body is HTML (default false) | | attachments | [{name, contentType, contentBytes}] | no | File attachments (max ~3MB each, base64-encoded) |

send_email

Same as draft_email plus:

| Parameter | Type | Required | Description | |---|---|---|---| | saveToSentItems | boolean | no | Save to Sent Items (default true) |

send_draft

| Parameter | Type | Required | Description | |---|---|---|---| | userEmail | string | yes | Mailbox address | | messageId | string | yes | Draft message ID |

list_drafts

| Parameter | Type | Required | Description | |---|---|---|---| | userEmail | string | yes | Mailbox address | | top | number | no | Max results 1–50 (default 10) |

delete_email — BLOCKED

Always returns OPERATION_BLOCKED error. Cannot be enabled.

Attachments

draft_email and send_email accept an optional attachments array. Each item must be:

{
  "name": "report.pdf",
  "contentType": "application/pdf",
  "contentBytes": "<base64-encoded file content>"
}

Limit: ~3MB per file (Microsoft Graph inline attachment limit). For larger files, an upload session is required (not currently supported).

Common MIME types:

| File type | contentType | |---|---| | PDF | application/pdf | | Word | application/vnd.openxmlformats-officedocument.wordprocessingml.document | | Excel | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet | | PNG | image/png | | JPEG | image/jpeg | | Plain text | text/plain |