In email communication, unwanted bulk email messages are commonly called by which term?

Introduction / Context:
This question belongs to basic internet and cyber security awareness. When people use email, they often receive unwanted messages that advertise products, promote scams or simply waste inbox space. These are known by a specific informal term that has become standard in both everyday language and technical literature. Knowing this term is important for understanding email filters, settings and security advisories that you see in popular email services.

Given Data / Assumptions:

• The messages in question are unwanted, bulk email messages sent to many recipients.
• The question calls this category junk email.
• Options include spam, spoof mail, sniffer script, spool file and cache mail.
• We assume typical email systems such as Gmail, Outlook or corporate mail servers.

Concept / Approach:
Junk email refers to email messages that are sent in large quantities without being requested by the recipient. They often consist of advertisements, fraudulent offers or links to malicious websites. The widely used term for such messages is spam. Email providers include spam filters that attempt to detect and move these emails to a dedicated spam or junk folder. Other terms in the options, such as spoof mail or sniffer script, refer to different security issues like identity faking or network sniffing. Spool and cache are related to internal system storage mechanisms. None of them is the general name for junk email. Therefore, spam is the correct answer.

Step-by-Step Solution:

Verification / Alternative check:
Open any major email service and look at the documentation or help topics about unwanted messages. You will find phrases like report this message as spam or spam filtering. Antivirus and security vendors also use the term spam for bulk unsolicited email in their educational articles. Technology news sites talk about spam campaigns and spam filters when reporting on email based attacks. This consistent and widespread usage across different platforms confirms that junk email is commonly called spam, not the other technical sounding options provided.

Why Other Options Are Wrong:

• Spoof mail: Spoofing refers to faking the sender address or identity, which can happen with spam but is not the general name for all junk email.
• Sniffer script: A sniffer is a tool that captures network traffic; sniffer scripts refer to malicious code that does this, not to unwanted email messages.
• Spool file: A spool is an area where print or email jobs are queued temporarily by the system; it is not a type of email.
• Cache mail: Cache refers to temporary storage for faster access; this is not a standard term for unwanted email.

Common Pitfalls:
Some learners may confuse spoof mail with spam because both are related to email abuse. However, spoofing is about identity deception and can also occur in legitimate looking messages, whereas spam refers primarily to the mass unsolicited nature of the messages. The presence of several technical sounding options can also cause guessing without careful reading. To avoid this, connect the question to everyday experience: you see a spam folder in your email account, not a spoof or sniffer folder. That simple observation points you to the correct term quickly.

Final Answer:
Junk or unwanted bulk email messages are commonly called Spam.