zerosmtp for Claude Code

io.github.msgwing/zerosmtp

A free SMTP relay that still takes a username and password, for devices that cannot do OAuth 2.0.

client:Claude Code transport:stdio runtime:npm

Install zerosmtp in Claude Code

run in your project directory

claude mcp add zerosmtp -- npx -y zerosmtp-mcp

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