io.github.msgwing/zerosmtp
zerosmtp
A free SMTP relay that still takes a username and password, for devices that cannot do OAuth 2.0.
alive probed 2026-10-19
4tools
≈ 342tokens, estimate
≈ 0.2 %of Claude's 200k window
0.2×the median server
97 msto initialize
3 msto list tools
- Run it
- npx -y zerosmtp-mcp@1.0.2 (stdio, probed in a container with the network off)
- Host
- npmjs.com
- Reports itself as
- zerosmtp 1.0.2
- Capabilities
- tools
- Instructions
- 399 characters
- Of a 1M window
- ≈ <0.1 % of a 1M context window, estimate
- Claude count
- The count_tokens endpoint refused the tool schemas: invalid x-api-key. The estimate stands in.
- Repository
- https://github.com/msgwing/ZeroSMTP
- Registry
- active, updated 2026-09-01 · registry entry
- Reachable
- 1 of the last 1 probe
Most expensive tools
Estimates with the o200k_base tokenizer.
| Tool | o200k estimate | Share of this server |
|---|---|---|
| check_relay_reachable | 109 | 32 % |
| check_device_oauth | 104 | 30 % |
| lookup_smtp_error | 81 | 24 % |
| relay_settings | 48 | 14 % |
Badge for the README
The result of the latest probe, the tool count and the token cost. The feed has an entry for every probe that changed them.
A mail when this server changes
Stops answering, comes back, tool set or cost changes. One confirmation mail first, a stop link in every mail.
For the publisher
- The Anthropic count_tokens endpoint refused the tool schemas (invalid x-api-key). A client that validates schemas can refuse them too.