Remite for ChatGPT

me.onmax/remite

Send a burofax or certified letter to a Spanish address, with proof of delivery and content.

client:ChatGPT transport:streamable-http tools:4

Install Remite in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://burofax.onmax.me/mcp/claude

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