Downloaded and installed the latest Mailspring. Saw in the release notes about MCP integration and got very excited. I enabled the MCP server, added to Claude Desktop, went over to Claude to try it and … failed.
Error log below:
2026-07-24T18:11:51.513Z [mailspring] [info] Initializing server... { metadata: undefined }
2026-07-24T18:11:51.526Z [mailspring] [info] Using MCP server command: /Applications/ServBay/script/alias/npx with path: {
metadata: {
paths: [
'/Users/Treehouse103/.local/bin',
'/Applications/ServBay/script/alias',
'/Applications/ServBay/bin',
'/Applications/ServBay/sbin',
'/Applications/ServBay/script',
'/Applications/ServBay/package/python/current/Python.framework/Versions/Current/bin',
'/Applications/ServBay/package/node/current/bin',
'/Applications/ServBay/package/go/current/bin',
'/Applications/ServBay/package/openjdk/current/bin',
'/Applications/ServBay/package/rust/current/bin',
'/Applications/ServBay/package/ruby/current/bin',
'/Applications/ServBay/package/dotnetsdk/current',
'/Applications/ServBay/package/dotnetsdk/current/tools',
'/Users/Treehouse103/.dotnet/tools',
'/Applications/ServBay/package/mono/current',
'/opt/homebrew/bin',
'/opt/homebrew/sbin',
'/usr/local/bin',
'/System/Cryptexes/App/usr/bin',
'/usr/bin',
'/bin',
'/usr/sbin',
'/sbin',
'/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin',
'/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin',
'/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin',
'//Applications/Topaz Photo AI.app/Contents/Resources/bin',
'/Users/Treehouse103/.cargo/bin',
[length]: 28
]
}
} %o
2026-07-24T18:11:51.528Z [mailspring] [info] Server started and connected successfully { metadata: undefined }
Error: Node.js executable for command 'npx' could not be found.
Checked ServBay (project config: '', default), NVM (NVM_BIN: '', alias/default), Homebrew, and system paths.
2026-07-24T18:11:51.570Z [mailspring] [info] Server transport closed { metadata: undefined }
2026-07-24T18:11:51.570Z [mailspring] [info] Server transport closed unexpectedly, this is likely due to the process exiting early. If you are developing this MCP server you can add output to stderr (i.e. `console.error('...')` in JavaScript, `print('...', file=sys.stderr)` in python) and it will appear in this log. { metadata: undefined }
2026-07-24T18:11:51.570Z [mailspring] [error] Server disconnected. For troubleshooting guidance, please visit our [debugging documentation](https://modelcontextprotocol.io/docs/tools/debugging) { metadata: { context: 'connection', stack: undefined } }
2026-07-24T18:11:51.570Z [mailspring] [info] Client transport closed { metadata: undefined }
2026-07-24T18:11:51.570Z [mailspring] [info] Client transport closed { metadata: undefined }