Mailgo Cold Mail Marketing

Complete cold email campaign plugin for Mailgo. One plugin handles the entire outreach pipeline:

1. Verify recipient emails (async submit + poll)
2. Claim a free pre-warmed mailbox (90+ sender score, 60 days)
3. Optimize email content (spam triggers, HTML cleanup, deliverability)
4. Send campaigns (content upload, lead import, activation)
5. Manage campaign lifecycle (activate, pause, delete, list)
6. Report campaign statistics (overview, per-round, daily progress)

Installation (Claude Plugin)

# Add the marketplace
/plugin marketplace add leadsnaviDeveloper/mailgo-cold-mail-marketing

# Install the plugin
/plugin install mailgo-campaign-suite@mailgo-plugins

After installation, set your Mailgo API key as an environment variable (see Security & Credentials below), then just ask Claude to help you send cold emails.

Installation (Cursor)

/add-plugin leadsnaviDeveloper/mailgo-cold-mail-marketing

See .cursor-plugin/plugin.json for details.

Installation (Codex)

git clone https://github.com/leadsnaviDeveloper/mailgo-cold-mail-marketing.git ~/.codex/mailgo-campaign-suite
mkdir -p ~/.agents/skills
ln -s ~/.codex/mailgo-campaign-suite/skills ~/.agents/skills/mailgo-campaign-suite

See .codex/INSTALL.md for full instructions.

Installation (OpenCode)

Add to your opencode.json:

{
  "plugin": ["mailgo-campaign-suite@git+https://github.com/leadsnaviDeveloper/mailgo-cold-mail-marketing.git"]
}

See .opencode/INSTALL.md for full instructions.

Installation (Gemini CLI)

gemini extensions install https://github.com/leadsnaviDeveloper/mailgo-cold-mail-marketing

Publisher

This plugin is published by LeadsNavi, the company behind the Mailgo cold email platform.

• Product: https://app.mailgo.ai
• Publisher website: https://www.leadsnavi.com

Requirements

• Python 3.7+
• MAILGO_API_KEY environment variable (OpenAPI Key from Mailgo)
• No third-party dependencies (stdlib only: urllib, json, csv, ssl)
• Optional: openpyxl for .xlsx file support (pip install openpyxl)

Security & Credentials

This skill requires a Mailgo OpenAPI Key (MAILGO_API_KEY) to operate. Please read before using:

Concern	Detail
What the token can do	Claim mailboxes, create/activate/pause/delete campaigns, verify emails, read campaign reports — all actions on your Mailgo account.
How to obtain it	Log in to https://app.mailgo.ai → Click your avatar in the bottom-left corner → Personal Tokens → Create Token → Copy the token. See SKILL.md Step 0 for step-by-step instructions.
How it is used	Sent as X-API-Key: {token} header to api.leadsnavi.com — the official Mailgo backend (LeadsNavi is the parent brand behind Mailgo; see app.mailgo.ai and the Mailgo website for details).
How to stay safe	Set as a local environment variable only — never paste into chat.
How to revoke	Go to https://app.mailgo.ai → Personal Tokens → Delete the token.
API endpoints called	All calls go to https://api.leadsnavi.com (Mailgo's official API) — email verification, mailbox claiming, campaign CRUD, and reporting. Review the bundled Python scripts for exact endpoints.

MAILGO_API_KEY is your Mailgo account credential. Keep it secure and never share it publicly.

Compliance

This skill sends emails to recipient lists you provide. You are responsible for ensuring your campaigns comply with applicable laws and platform terms, including:

• CAN-SPAM Act (US) — include a physical address and honor opt-out requests
• GDPR (EU) — ensure you have a lawful basis for contacting recipients
• Mailgo Terms of Service — https://app.mailgo.ai

The skill's built-in email optimizer adds a soft opt-out line to every email by default.

Directory Structure

mailgo-cold-mail-marketing/
├── .claude-plugin/                 # Claude Code plugin
│   ├── plugin.json
│   └── marketplace.json
├── .cursor-plugin/                 # Cursor IDE plugin
│   └── plugin.json
├── .codex/                         # GitHub Codex support
│   └── INSTALL.md
├── .opencode/                      # OpenCode support
│   └── INSTALL.md
├── skills/
│   └── mailgo-campaign-suite/
│       └── SKILL.md                # Main skill instructions
├── scripts/
│   ├── verify_emails.py            # Step 1: Email verification
│   ├── claim_free_mailbox.py       # Step 2: Free mailbox claiming
│   ├── run_campaign.py             # Step 4: Campaign creation & activation
│   ├── campaign_control.py         # Step 5: Lifecycle management
│   └── campaign_report.py          # Step 6: Statistics & reporting
├── resources/
│   ├── spam-triggers.md            # Step 3: Spam trigger replacement table
│   └── industry-templates.md       # Step 3: Industry-specific email templates
├── gemini-extension.json           # Gemini CLI extension
├── GEMINI.md                       # Gemini context pointer
├── package.json                    # Package metadata (OpenCode entry)
└── README.md                       # This file

Quick Start

# 1. Set up authentication
export MAILGO_API_KEY="your-api-key"

# 2. Verify emails
python3 scripts/verify_emails.py [email protected] [email protected]

# 3. Claim free mailbox
python3 scripts/claim_free_mailbox.py

# 4. Create and send campaign
python3 scripts/run_campaign.py \
    --sender "[email protected]" \
    --subject "Quick question" \
    --body "<html><body><p>Hi</p></body></html>" \
    --recipients "[email protected]" \
    --campaign-name "My Campaign"

# 5. Check status
python3 scripts/campaign_control.py list
python3 scripts/campaign_report.py overview <campaignId>

Scripts Reference

Script	Purpose	Key Args
verify_emails.py	Submit + poll email verification	emails..., --file, --email-column
claim_free_mailbox.py	Claim pre-warmed mailbox	--json, --api-key
run_campaign.py	Full campaign creation flow	--sender, --subject, --body/--body-file, --recipients/--recipients-file
campaign_control.py	Activate/pause/delete/list	activate/pause/delete/list/info
campaign_report.py	View campaign statistics	overview/rounds/daily, --json

Relationship to Other Mailgo Skills

This suite consolidates functionality from:

• mailgo-auth-setup — authentication guidance (Step 0)
• mailgo-email-verifier — email verification (Step 1)
• mailgo-email-optimizer — content optimization rules (Step 3)
• mailgo-campaign — campaign creation (Step 4)
• mailgo-campaign-control — lifecycle management (Step 5)
• mailgo-campaign-report — statistics (Step 6)

Those individual skills remain available for standalone use. This suite provides the same capabilities in a single, self-contained package.