SMTP MCP Server

email_send

Send new email messages with optional HTML formatting and file attachments. Supports CC, BCC, and custom sender addresses for project updates or any email conversation.

Instructions

Send a new email with HTML support and file attachments. Use this to send messages, project updates, or any new email conversation.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "to": "<to>",
      "subject": "<subject>",
      "body": "<body>"
    },
    "name": "email_send"
  }
}

Input Schema

Name	Required	Description	Default
`cc`	No	Array of CC recipient email addresses
`to`	Yes	Array of recipient email addresses
`bcc`	No	Array of BCC recipient email addresses
`body`	Yes	Email body content (can be plain text or HTML)
`subject`	Yes	Email subject line
`body_type`	No	Body format: 'plain' for plain text or 'html' for HTML content	html
`from_email`	No	Optional sender address. When sender_emails is configured for the account, the address must be in that allowlist.
`attachments`	No	Array of file attachments
`account_name`	No	Name of the email account to use

Schema Changelog

Changes observed during successful MCP inspections.

Addedv2.2.0Aug 14, 2026

TDQS

A3.6/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden, but it only repeats schema details like HTML support and attachments. It does not disclose side effects, authentication requirements, or other behavioral traits beyond what the schema already lists.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, front-loaded with the main action, and no wasted words. Every sentence serves a purpose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with 9 parameters and no output schema, the description is too thin. It omits any information about return values, potential errors, or constraints like the sender allowlist noted in the schema's from_email property.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so baseline is 3. The description adds no extra meaning beyond naming HTML and attachments, which are already in the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's function: 'Send a new email with HTML support and file attachments.' It distinguishes itself from sibling tools like email_respond by emphasizing 'new email conversation.'

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides clear usage context: 'Use this to send messages, project updates, or any new email conversation.' However, it doesn't explicitly exclude alternatives like email_respond, but the 'new email' phrasing implies the boundary.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server