add-mail-attachment

SERVERMs 365 SOURCE@jo3zik/ms-365-mcp-server

Medium RISK CLASS

Category Write

Parameters 52 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/jo3zik-ms-365-mcp-server/add-mail-attachment.md

WHAT IT DOES

What add-mail-attachment does on Ms 365

AI agents use add-mail-attachment to create or update resources in Ms 365, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Ms 365 environment.

Parameter	Type	Required	Description
`body`	object	Yes
`confirm`	boolean	—	For destructive operations when the confirm gate is enabled (MS365_MCP_REQUIRE_CONFIRM=true; off by default). Set to true only after the user has explicitly app
`messageId`	string	Yes	Value for the 'messageId' path segment. Pass it under the name 'messageId', not as 'id'. Use the 'id' field of the message object as returned by Microsoft Graph
`includeHeaders`	boolean	—	Include response headers (including ETag) in the response metadata
`excludeResponse`	boolean	—	Exclude the full response body and only return success or failure indication

Parameters from the server's own tool schema.

RISK

Why add-mail-attachment is rated Medium

An AI agent can call add-mail-attachment faster than any human can review: one bad instruction and it creates or modifies resources in Ms 365 by the hundred, each call as confident as the last.

Risk signalsAccepts raw HTML/template content (body) · High parameter count (11 properties)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs add-mail-attachment safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Ms 365, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For add-mail-attachment, this is the rule to start with:

add-mail-attachment Rate-limited

add-mail-attachment stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "add-mail-attachment": {
      "limits": [
        {
          "counter": "add-mail-attachment_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Ms 365, apply this rule, and every add-mail-attachment call is checked against it from then on.

FAQ

Questions about add-mail-attachment

What does the add-mail-attachment tool do? +

Use this API to create a new Attachment. An attachment can be one of the following types: All these types of attachment resources are derived from the attachment resource. 💡 TIP: The only path for attachments under 3MB. contentBytes must carry the complete base64 verbatim; a truncated argument fails with 400 UnableToDeserializePostBody. At 3MB and above use create-mail-attachment-upload-session, which rejects anything smaller. Body requires @odata.type: {"@odata.type": "#microsoft.graph.fileAttachment", "name": "file.pdf", "contentBytes": "<base64>"}. It is categorised as a Write tool in the Ms 365 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does add-mail-attachment accept? +

add-mail-attachment accepts 5 parameters: body, confirm, messageId, includeHeaders, excludeResponse. Required: body, messageId. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on add-mail-attachment? +

Register the Ms 365 MCP server in PolicyLayer and add a rule for add-mail-attachment: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Ms 365. Nothing to install.

What risk level is add-mail-attachment? +

add-mail-attachment is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit add-mail-attachment? +

Yes. Add a rate_limit block to the add-mail-attachment rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block add-mail-attachment completely? +

Set action: deny in the PolicyLayer policy for add-mail-attachment. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides add-mail-attachment? +

add-mail-attachment is provided by the Ms 365 MCP server (@jo3zik/ms-365-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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