Definition: directory harvest attack
A method spammers use to obtain valid email addresses. Random names are generated and sent out to valid domains. If an undeliverable message does not return, the name 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 email@example.com or firstname.lastname@example.org.