Peter, a malicious hacker, obtains e-mail addresses by harvesting them from postings, blogs, DNS listings, and Web pages. He then sends large number of unsolicited commercial e-mail (UCE) messages…

Email spoofing involves forging the From or header fields to make an email appear to originate from a different sender, which is not described in this scenario.

Email bombing targets a single recipient or server with an overwhelming volume of messages to cause a denial-of-service effect, not mass unsolicited commercial messaging to many harvested addresses.

An email storm is an uncontrolled chain reaction of reply-all responses within an organization that floods inboxes, not a deliberate harvesting-and-spam campaign by an external attacker.

Email spam is defined as the mass distribution of unsolicited commercial or bulk email to recipients who have not requested it, often sourced from harvested address lists gathered from public web pages, DNS records, newsgroups, and blogs. Peter's activity - automated harvesting followed by bulk UCE delivery - matches the textbook definition of spamming.