What is a Directory Harvest Attack, DHA?
A Directory Harvest Attack (DHA) is a sophisticated technique that spammers use to bypass typical email server checking mechanisms in order to access directories and receive a list of valid email addresses. During a DHA, spammers attempt to deliver messages to multiple addresses, such as john@yourcompany.com, jane@yourcompany.com, or mary@yourcompany.com. Addresses that are not rejected by the receiving mail server are determined as valid. These addresses are compiled and sold to other spammers worldwide. This is why a brand new email box can be full of unsolicited junk email just hours after it has been set-up. Our service protects against Directory Harvest Attacks.
