When a user registers or changes their email in their account, the plugin sends a letter with a confirmation link to the specified email. This is how the email is confirmed.
After activation, the plugin creates a settings page "Settings" - "Email confirmation before registration"
On this page, you can sеlect a timeout (the time after which the next letter will be sent for the current email).
The email is confirmed for the user's session for 5 days, then you need to confirm the email again.