Configure settings

Some skills need configuring like the email skill needs the email to work.
Is there a way to find all the skill that need configuring through the files of the skill?

Thank You

Configurable skills can be done thought https://home.mycroft.ai/skills (if you want a user-friendly way to do it) or editing the needed files specified in each skill (if you are a privacy advocate and refuses to put your data on Mycroft.AI servers).
In the case of the email skill, if you go to the marketplace or github, the skill developer explains how to configure it in both cases.
https://github.com/LinusS1/email-skill/wiki/Configuration

The Skills settings page is certainly the most user friendly way.

On device though, any Skill with settings will have a settingsmeta.json or settingsmeta.yaml file so to get a list of the directories containing those files you could run:
find /opt/mycroft/skills/ -name "settingsmeta.*"