According to the Department of Homeland Security, which package characteristic should raise suspicion?

Packages with excessive postage stamps can raise suspicion because they may indicate that the sender is attempting to disguise the true nature of the package. This characteristic can suggest that the package was sent from an unusual location or that the sender is trying to avoid detection or adherences to standard mailing practices. In addition, excessive postage could be a sign of an attempt to circumvent regular postal regulations, which may imply that the contents are suspicious or hazardous. In contrast, a standard address format, a well-known sender, and clear, correct spelling are typically indicators of legitimate correspondence and do not usually trigger the same level of concern.