Best Alternatives to TheHarvester Cloud Email & Subdomain Finder

Lumail

Runtime: npx

Official Lumail email marketing MCP for campaigns, subscribers, and workflows.

Telnyx

Runtime not confirmed

Official TypeScript library for the Telnyx API

Line Bot MCP Server

Runtime: npx

Verified

Connects an AI agent to LINE Messaging API for messaging, user profiles, quotas, followers, and rich-menu management.

Atomic Mail

Runtime: npx

Programmable email inbox for AI agents — JMAP, PoW auth, stdio MCP server.

Engagelab Email

Runtime: npx

Send, receive, monitor and reply to email from AI agents with threaded inbox context.

Google Workspace

Runtime: npx

Give AI agents access to Gmail, Calendar, Drive, and more — multi-account, manifest-driven

Emailmd

Runtime: npx

Render, lint, and preview markdown emails through MCP using hosted HTTP or local stdio transport.

Signaliz

Runtime: npx

B2B email verification, company signal enrichment, and governed GTM data pipelines.

E2a — email for AI agents

Runtime: uvx

Authenticated email gateway for AI agents — per-agent inboxes, HITL approval, SPF/DKIM verified.

Byteplant MCP

Runtime: uvx

An MCP server that provides Email, Phone and Address Validation Services from Byteplant

Microsoft Outlook MCP

Runtime: npx

Microsoft Outlook (mail) MCP server — read, search, and send email through Microsoft Graph.

Mailbuttons

Runtime: npx

Governed email for AI agents: sandbox inboxes, server-side policy gate, tamper-evident audit.