How can malware be delivered via email?

Malware can be delivered via email primarily through malicious attachments or links, which is the answer highlighted. Attachments such as executable files, documents with macros, or other file types can carry malware that becomes active when the user opens the attachment. Similarly, links embedded in emails can redirect recipients to compromised websites that automatically download malware onto the user's device or lead to phishing sites designed to harvest personal data.

The effectiveness of this delivery method comes from the fact that email communication is ubiquitous and users often trust messages that appear to be from known contacts or recognizable senders. By tricking individuals into downloading an attachment or clicking a link, attackers can exploit common behaviors and assumptions about email security.

Other options presented do not relate to malware delivery in the same direct manner. For example, untracked email addresses typically do not enhance the delivery of malware, as it is the content of the email that poses the threat rather than the address itself. Pop-up messages from email programs are usually a byproduct of user actions and not a method through which malware is spread. Encrypted email conversations, while enhancing privacy and security, do not inherently deliver malware; they merely protect the content of emails from unauthorized access.

Therefore, the option concerning attachments or links stands out as the primary