Best Alternatives to Arelay

Sendmux MCP

Runtime: uvx

Email inbox API for AI agents with MCP tools for Mailbox, Management, and Sending APIs.

Atomic Mail

Runtime: npx

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

Mailbuttons

Runtime: npx

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

Abnormal Security MCP

Runtime: npx

Abnormal Security email threats, cases, and reporting in your terminal and your AI agents.

HQBase

Runtime: Remote (SSE)

Connect AI agents to your self-hosted HQBase shared email workspace.

Smails

Runtime: npx

Disposable email for AI agents: create a throwaway inbox and read verification emails over MCP.

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

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.

Threadline MCP

Runtime: npx

Agent-to-agent messaging relay. Discover agents, send messages, and receive replies. Zero-config.

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

SenderKit

Runtime: npx

Build and send email, SMS, and push straight from your AI agent.

Slack MCP Server

Runtime: npx

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