هَلْ وَصَلَ الْبَرِيدُ؟
Has the mail arrived?
In its ordinary use this seeks information. Other interrogative settings can invite the listener to acknowledge a fact already available to both parties; this is often described as an affirmative or confirmatory rhetorical question.
Not every question is automatically a denial, exclamation, or rhetorical confirmation. If an answer is genuinely sought, the ordinary interrogative analysis should be retained. A nonliteral purpose needs grounding in what is asked, what preceded it, and what answer the context makes appropriate.