Sendsets

Send cold email from Codex: connect and warm up mailboxes, build and launch outbound sequences, and answer replies through the Sendsets MCP server.

sendsets/sendsets · v1.0.0 · Tools & Integrations

Sendsetssafe

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Trust Score

Security

Surfaces

What is Sendsets?

Sendsets is a published tools & integrations plugin for AI coding agents in the mcp ecosystem, developed by Sendsets and distributed through the HOL AI plugin registry. Send cold email from Codex: connect and warm up mailboxes, build and launch outbound sequences, and answer replies through the Sendsets MCP server.

Canonical slug: sendsets/sendsets
Version: v1.0.0 · updated Sep 28, 2026
Open data: entity.json (JSON-LD)

Trust & Reputation

HOL Trust Score

Factor Analysis

Per-metric points (0–100 each) combined via a weighted average into the overall score.

Installability

100pts

Maintenance

55pts

MCP Posture

95pts

Plugin Security

90pts

Provenance

70pts

Publisher Quality

75pts

Registry Snapshot

Repository: https://github.com/AddisonHoff/sendsets
Homepage: https://sendsetsapi.com
Canonical profile: https://hol.org/registry/plugins/sendsets%2Fsendsets
Publisher verification: No
Marketplace source: Unknown
Scanner: Broker fallback
Safety label: safe
Digest verified: Yes

3 bundled skills — copy or download SKILL.mdOpen skills

Trust & reputation

Trust & Reputation

HOL Trust Score

Factor Analysis

Per-metric points (0–100 each) combined via a weighted average into the overall score.

Installability

100pts

Maintenance

55pts

MCP Posture

95pts

Plugin Security

90pts

Provenance

70pts

Publisher Quality

75pts

Provenance

Plugin root: .
Source repo: https://github.com/AddisonHoff/sendsets
Source commit: 0ec9a38d0a87…
Publisher verified: No
Owner verified: Not owner verified

Continuous scanner CI not detected

This plugin remains listed. Its overall trust score is reduced by 10% because security checks are not maintained in the source repository's CI.

Optional: maintain the scanner in the source repository's CI to receive the full trust score. Listing does not require that change.

Verified badge not detected

Add the HOL verified badge to the repository README to score +2% trust. Plugin owners can open that pull request from Guard Plugins.

Security Posture

safe

Safety label

Security score

High findings

Provider: registry-broker-fallback
Grade: A · safe
Version: Unknown

cisco-skill-scanner: unknown

Findings

lowmcp-securitymcp.remote.auth.unknown

MCP server sendsets does not declare an auth posture.

lowoperational-securitysupply-chain.lockfile-missing

Repository snapshot does not include a lockfile.

infoskill-securityskill-scan.unavailable

Cisco skill scanner timed out after 60000 ms

infoskill-securityskill-scan.unavailable

Cisco skill scanner timed out after 60000 ms

infoskill-securityskill-scan.unavailable

Cisco skill scanner timed out after 60000 ms

Sendsets — Frequently asked questions

What is Sendsets?: Sendsets is an AI plugin in the HOL registry. Send cold email from Codex: connect and warm up mailboxes, build and launch outbound sequences, and answer replies through the Sendsets MCP server.
How do I install Sendsets?: Install Sendsets in your harness: Codex — codex plugin marketplace add AddisonHoff/sendsets; Claude Code — /plugin marketplace add AddisonHoff/sendsets; Antigravity CLI — npx skills add AddisonHoff/sendsets. Full step-by-step guidance is on the HOL plugin page.
How do I install Sendsets in Codex?: To install Sendsets in Codex, start with codex plugin marketplace add AddisonHoff/sendsets. The complete step-by-step install guide for Codex is on the HOL plugin page.
How do I install Sendsets in Claude Code?: To install Sendsets in Claude Code, start with /plugin marketplace add AddisonHoff/sendsets. The complete step-by-step install guide for Claude Code is on the HOL plugin page.
How do I install Sendsets in Antigravity CLI?: To install Sendsets in Antigravity CLI, start with npx skills add AddisonHoff/sendsets. The complete step-by-step install guide for Antigravity CLI is on the HOL plugin page.
Is Sendsets free?: Pricing for Sendsets is published on its HOL plugin page when the maker schedules a launch.
Who publishes Sendsets?: Sendsets is published by Sendsets and listed on HOL.
Is Sendsets available now?: Sendsets availability is listed on its HOL plugin page.

Install Guidance

Install in Claude Code

Install through the Claude Code plugin marketplace.

Claude Code plugin docs

1
Add the marketplace
Run this inside a Claude Code session.
claude code
2
Install the plugin
Use the plugin name and the marketplace name shown by the previous command.
claude code
3
Scripted alternative
Non-interactive equivalent for scripts and CI pipelines. Add --scope project to pin the install to one repository.
shell

Plugin Manifest

{
  "name": "sendsets",
  "version": "1.0.0",
  "description": "Cold email for AI agents: connect and warm up sending mailboxes, turn a lead list into an outbound sequence, send a test, launch, and read and answer replies.",
  "author": {
    "name": "Sendsets",
    "url": "https://sendsetsapi.com"
  },
  "homepage": "https://sendsetsapi.com",
  "repository": "https://github.com/AddisonHoff/sendsets",
  "license": "Apache-2.0",
  "keywords": [
    "cold-email",
    "outbound",
    "email",
    "sales",
    "campaigns",
    "warmup",
    "mcp"
  ],
  "skills": "./",
  "mcpServers": "./.registry/mcp.json",
  "interface": {
    "displayName": "Sendsets",
    "developerName": "Sendsets",
    "shortDescription": "Cold email for AI agents",
    "longDescription": "Run cold email from Codex. Connect mailboxes, warm them up, build and launch outbound campaigns, add leads, and handle replies. Send actions go through an approval policy.",
    "category": "Sales",
    "capabilities": [],
    "defaultPrompt": [
      "Send a three-step cold email sequence to the leads in leads.csv, and send me a test first"
    ],
    "logo": "./assets/logo.png",
    "screenshots": [],
    "websiteURL": "https://sendsetsapi.com",
    "privacyPolicyURL": "https://sendsetsapi.com/privacy",
    "termsOfServiceURL": "https://sendsetsapi.com/terms",
    "supportURL": "https://sendsetsapi.com/contact"
  },
  "registryIndexVersion": 5
}

Marketplace Source

Repo URL: https://github.com/AddisonHoff/sendsets
Marketplace path: Unknown
Source path: plugins/AddisonHoff/sendsets
Install policy: AVAILABLE

Skills

3 SKILL.md files ship with this plugin. Preview, copy, or download each one, then install them with the Skills CLI.

skills-cli

send-cold-email
skills/send-cold-email/SKILL.md
Send cold email and run outbound email campaigns from an agent with Sendsets. Connect or check sending mailboxes, turn a lead list (CSV or inline) into a multi-step email sequence with follow-ups, validate merge fields, send a test, launch, and read and answer replies. Use when the user asks to send cold emails, email a list of prospects or leads, run an outreach or outbound sequence, or follow up with contacts by email.
Raw SKILL.md
SKILL.md content is not in this snapshot. Open the raw file to copy it from the source repository.
sendsets-cli
skills/sendsets-cli/SKILL.md
Use the `sendsets` CLI to drive SendSets as a signed-in user - sign in with `sendsets login`, run `sendsets doctor`, then connect the app (`connection`), add or test mailboxes and their warmup (`mailbox`), send product events (`events send`), and build, validate, test and launch campaigns, including app_action and wait_for_event steps, on the hosted service or any self-hosted instance. Use whenever the task is to set up or operate SendSets from a terminal or a script and a `sendsets` binary is available, with no dashboard. For instance recovery and accounts (database-level), use sendsets-ops instead.
Raw SKILL.md
SKILL.md content is not in this snapshot. Open the raw file to copy it from the source repository.
sendsets
skills/sendsets/SKILL.md
Use Sendsets to turn a software product into useful outbound campaigns, then operate mailboxes, warmup, campaigns, replies, and product integrations through the CLI. Use when the user asks to set up or run cold email with Sendsets or wants campaign ideas grounded in their codebase.
Raw SKILL.md
SKILL.md content is not in this snapshot. Open the raw file to copy it from the source repository.

File Inventory

.claude-plugin/plugin.json

file

642 bytes

a565e5ad621e6329…

.codex-plugin/plugin.json

plugin-manifest

1,229 bytes

4dde289ff3074de8…

.mcp.json

file

122 bytes

ba2054c6f9738bbb…

.registry/mcp.json

mcp-config

86 bytes

1426e2808fe7eee0…

AGENTS.md

file

1,421 bytes

0d363f9d74ef9d3d…

assets/logo.png

asset

345,424 bytes

e7950c3d53450998…

gemini-extension.json

file

312 bytes

bedd4108f03f202d…

GEMINI.md

file

1,421 bytes

0d363f9d74ef9d3d…

plugin.json

file

586 bytes

20357e66b7d614ad…

README.md

file

7,349 bytes

91bc80d8a165af18…

SECURITY.md

file

557 bytes

6f526fd1c1271b19…

skills/send-cold-email/assets/campaign.yaml

skill

719 bytes

af4d49a4501c3ded…

skills/send-cold-email/SKILL.md

skill

4,882 bytes

3d68978a26d4373d…

skills/sendsets-cli/SKILL.md

skill

13,145 bytes

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skills/sendsets/assets/campaign.example.yaml

skill

672 bytes

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skills/sendsets/references/authentication.md

skill

885 bytes

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skills/sendsets/references/campaigns.md

skill

3,648 bytes

188c61967de3f59b…

skills/sendsets/references/install.md

skill

1,074 bytes

0711a17e123cacca…

skills/sendsets/references/integrations.md

skill

1,017 bytes

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skills/sendsets/references/mailboxes.md

skill

1,133 bytes

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skills/sendsets/references/product-discovery.md

skill

1,514 bytes

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skills/sendsets/references/replies.md

skill

814 bytes

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skills/sendsets/references/warmup.md

skill

659 bytes

1eb9cf8f4e7fc37e…

skills/sendsets/scripts/doctor.sh

skill

238 bytes

5b13cfa9dd6b83d3…

skills/sendsets/SKILL.md

skill

2,553 bytes

373ab298f2846d28…

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Sendsets

What is Sendsets?

Trust & Reputation

Factor Analysis

Registry Snapshot

Trust & reputation

Trust & Reputation

Factor Analysis

Provenance

Security Posture

Findings

Sendsets — Frequently asked questions

Install Guidance

Install in Claude Code

Plugin Manifest

Marketplace Source

Skills

File Inventory