Best Alternatives to Threadline MCP

Engagelab Email

Runtime: npx

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

AgentLair

Runtime: npx

Give AI agents a real @agentlair.dev email address and encrypted vault. Send/receive email.

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.

Slack MCP Server

Runtime: Remote (SSE)

MCP server providing Slack workspace data access with message history, threads, DMs, user info, and optional message posting.

Google Workspace

Runtime: npx

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

Telegram MCP

Runtime: npx

Telegram API MCP server for accessing user data, dialogs, messages, and managing read status.

Faithk7 Gmail MCP

Runtime: npx

Manage Gmail messages, threads, labels, drafts, and settings from your workflows. Send and organiz…

Domani

Runtime: npx

Domains + send/receive email + inbound webhooks + DNS for AI agents. One API, MCP, CLI.

Arcxs MCP Server

Runtime: npx

Universal AI agent registry, cross-protocol discovery, messaging, and payment routing.

Give your AI agents a real WhatsApp number to send and receive messages.

Dead Simple Email

Runtime: uvx

Give an agent its own inbox: send, receive, and pull signup codes from real email.

Emailmd

Runtime: npx

Convert markdown to email-safe HTML with linting and live preview via an MCP server or local CLI.