There are vendors like Emailage that somehow determine the age of email addresses. Very useful because fraudsters tend to buy credit cards and bank accounts, then need to complete the identity by registering an email address for that identity.

Historically, outlook emails have been very easy for this compared to gmail addresses, which require phone numbers, etc.

One of the reasons "aged" account marketplaces got more popular. People buy from vendors that farm a ton of these accounts and wait to sell them, or those reselling compromised accounts (especially with EDU accounts before institutions actually implemented security controls).