A method spammers use to obtain valid email addresses. In a directory harvest attack, random names are generated and sent out to valid domains. If an undeliverable message does not return, the address is assumed to be genuine. Random names are easy to generate from any electronic phone book because many organizations standardize on conventions such as first name letter and last name or first name and last name letter; for example, John Doe could be jdoe@xyz.com or johnd@xyz.com. See
spam.