What is the use of is_email

What is the use of is_email_verified & is_email_valid, when in the signup flow, we already ask user with email and phone number validity and verify?

In which scenario will this be falsy?
When is is_email_verified = false & when is is_email_valid = false?

Hello

field desc
$.kakao_account.is_email_valid Whether email address is valid.
If the email has expired because it is used for another Kakao Account, false is returned.
$.kakao_account.is_email_verified Whether email address is verified.

“is_email_verified” is a legacy feature, and since email verification is now required, this value will no longer be set to false.
“is_email_valid” becomes false when the email is occupied by another account, and from that point, the email will be partially masked when provided.