[Fortunately, she didn't take it as an insult so much as an opportunity to reaffirm her role, so she nods, back to her usual pleasant tone.] Yes, it is quite alright, but there are a few stipulations.
You will have to register the package here with me, so that I will know your identity. If you place an unlabeled package in the drop box, I will not deliver it.
And you must also consent to the receiving parties to ask for your identity should they desire to know. We have had concerns in the past about dangerous parcels sent anonymously.