Which of the following is a characteristic of suspicious mail?

Excessive postage is a characteristic often associated with suspicious mail because it can indicate an attempt to conceal the true nature of the item or to draw attention in a way that might seem unusual for standard mail. In many cases, individuals sending harmful or illicit materials may use significantly more postage than necessary to avoid suspicion or to ensure their package reaches its destination despite the content. This discrepancy can serve as a red flag for postal employees tasked with identifying potential threats.

In contrast, options such as a clearly visible return address, well-formatted and typed address, and targeting a specific individual typically signify legitimate correspondence. These characteristics alone do not raise immediate concerns over the mail's content and may indicate that the item is conventional mail rather than suspicious. The focus on excessive postage helps postal workers remain vigilant by recognizing atypical mailing practices that could warrant further investigation.