MailStream for Claude Code

app.mailstream/mailstream

The first MCP server for physical mail: send postcards and letters, manage lists and campaigns.

client:Claude Code transport:streamable-http

Install MailStream in Claude Code

run in your project directory

claude mcp add --transport http mailstream https://my.mailstream.app/mcp

Adds it for this project only. Append --scope user to make it available everywhere. Claude Code docs