MailSnail for ChatGPT

io.github.iancollins27/mailsnail

Send USPS letters & certified mail from any agent. Hosted: sign in, no install.

client:ChatGPT transport:streamable-http runtime:npm

Install MailSnail in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://api.mailsnail.dev/mcp

Custom connectors are a paid-plan feature and take a remote URL only. ChatGPT cannot run a packaged server locally. ChatGPT docs