In Internet use, an email bomb is a form of net abuse consisting of sending huge volumes of email to an address in an attempt to overflow the mailbox or overwhelm the server where the email address is housed in a denial of service attack. Bulk mail consists of sending numerous duplicate emails to the same email address. These types of email bombs are simple to design, but their extreme simplicity means they can be easily detected by spam filters. E-mail bombardment using mass mail is also commonly done as a DDoS attack by employing the use of "zombie" botnets; Hierarchical networks of computers compromised by malware and under the control of the attacker. Similar to its use in spamming, the attacker directs the botnet to send millions or even billions of emails, but unlike normal spam, emails are directed to only one or a few addresses that the attacker want to flood. This form of e-mail bombing is similar to other DDoS flood attacks. As the targets are often dedicated hosts that handle the website and email accounts of a company, this type of attack can be so devastating for both host services.