Mailbox verification typically involves several steps:
Syntax Check: The email address is checked against standard email format rules to ensure it is correctly formatted. Domain Check: The domain of the email address is verified to confirm that it is active and can receive emails. MX Record Check: The Mail Exchange (MX) records of the domain are checked to ensure the domain has active mail servers. SMTP Check: A connection is attempted to the mail server to verify that the specific email address exists and can receive messages.