[BUG] "Unknown user/project config" warning about "email"

Is there an existing issue for this?

• I have searched the existing issues

This issue exists in the latest npm version

• I am using the latest npm

Current Behavior

npm prints the following warning on the console:

npm warn Unknown user config "email". This will stop working in the next major version of npm.

The "email" property is documented. npm shouldn't complain about it.

There's another similar issue #8153, but it's about custom properties in .npmrc.

Expected Behavior

No warning about the "email" property.

Steps To Reproduce

1. With the latest Node.js 24 LTS and the latest npm.
2. With email=user@domain.com in ~/.npmrc.
3. Run 'npm --version`.
4. See the warning appear.

❯ npm --version --verbose
npm verbose cli /Users/prantlf/.nodeup/24.11.0/bin/node /Users/prantlf/.node/bin/npm
npm info using npm@11.6.2
npm info using node@v24.11.0
npm warn Unknown user config "email". This will stop working in the next major version of npm.
11.6.2
npm verbose cwd /home/prantlf
npm verbose os Darwin 24.6.0
npm verbose node v24.11.0
npm verbose npm  v11.6.2
npm verbose exit 0
npm info ok

❯ node --version
v24.11.0

❯ echo $NODE_OPTIONS

Environment

• npm: 11.6.2
• Node.js: 24.11.0
• OS Name: MacOS 15.7.1
• System Model Name: MacBook Pro 2018
• npm config:

//registry.npmjs.org/:_authToken=...
email=prantlf@gmail.com

init-author-name=Ferdinand Prantl
init-author-email=prantlf@gmail.com

save-prefix=^
package-lock=true
audit=true

Reproduce the warning with email=user@domain.com in ~/.npmrc and npm --version --verbose using the reported npm and Node.js versions. Trace npm's configuration validation for the documented email property; done means the command no longer warns about that property while other unknown user-config warnings remain appropriate.