Send email using MailChannels Email API

• Outcome: Pass
• Latest audit: Sep 10, 2026 · 8:00 AM UTC
• Version: 1.0.0

Overview

This is a concise MailChannels integration guide whose external API use and webhook setup match its stated email-sending purpose.

Before installing, confirm you intend to let the agent send email through your MailChannels account and configure only narrowly scoped webhook routes. Protect the API key, validate webhook signatures as instructed, and avoid mapping incoming hooks to broad or sensitive agent actions.

A.I.G

Vulnerability Patterns

• Skill Instruction Hijacking: Alters the agent's session goals or safety constraints when the skill loads
• Agent Memory Poisoning: Writes attacker-controlled rules into memory that affect later sessions
• Remote Payload Retrieval and Execution: Fetches external code whose behavior can change after review
• Embedded Malicious Code: Ships malicious scripts inside the skill and executes them locally
• Unauthorized Access and Privilege Escalation: Obtains permissions beyond the task's legitimate needs

SkillSpector

Vulnerability Patterns

• Data Exfiltration: External Transmission, Env Variable Harvesting, File System Enumeration
• Tool Misuse: Tool Parameter Abuse, Chaining Abuse, Unsafe Defaults
• Rogue Agent: Self-Modification, Session Persistence
• Prompt Injection: Instruction Override, Hidden Instructions, Exfiltration Commands
• Privilege Escalation: Excessive Permissions, Sudo/Root Execution, Credential Access

Findings (4)

Tool Parameter Abuse

High

• Category: Tool Misuse
• Confidence: 80% confidence

Finding

Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Content

Scanner excerpt · SKILL.md (reported line 29)May include surrounding context.

md

Base URL: `${MAILCHANNELS_BASE_URL:-https://api.mailchannels.net/tx/v1}`
- Send: `POST /send`
- Send async: `POST /send-async`
- Webhook: `POST /webhook?endpoint=<url>`, `GET /webhook`, `DELETE /webhook`, `POST /webhook/validate`
- Public key: `GET /webhook/public-key?id=<keyid>`

## Sending Email

External Transmission

Medium

• Category: Data Exfiltration
• Confidence: 50% confidence

Finding

Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

Content

Scanner excerpt · SKILL.md (reported line 17)May include surrounding context.

md

- `MAILCHANNELS_ACCOUNT_ID` (aka `customer_handle`)

Optional:
- `MAILCHANNELS_BASE_URL` (default: `https://api.mailchannels.net/tx/v1`), `MAILCHANNELS_WEBHOOK_ENDPOINT_URL`

## Domain Lockdown (DNS)

External Transmission

Medium

• Category: Data Exfiltration
• Confidence: 50% confidence

Finding

Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

Content

Scanner excerpt · SKILL.md (reported line 26)May include surrounding context.

md

- `MAILCHANNELS_ACCOUNT_ID` (aka `customer_handle`)

Optional:
- `MAILCHANNELS_BASE_URL` (default: `https://api.mailchannels.net/tx/v1`), `MAILCHANNELS_WEBHOOK_ENDPOINT_URL`

## Domain Lockdown (DNS)

Session Persistence

Medium

• Category: Rogue Agent
• Confidence: 60% confidence

Finding

Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.

Content

Scanner excerpt · SKILL.md (reported line 21)May include surrounding context.

md

## Domain Lockdown (DNS)

Create a TXT record for each sender domain:
- Host: `_mailchannels.<your-domain>`
- Value: `v=mc1; auid=<YOUR_ACCOUNT_ID>`

Static analysis

No suspicious patterns detected.