The reason I said what I said is the OP doesn't accept private messages. Not always, but that is the usual MO for a spammer.
I'd like to be wrong. Hopefully the OP comes back, shows what code they written to solve the assignment and asks a question so we can help them if at all possible.
I vaguely remembered it being the opposite, default was accepting new messages.
It seems logical that accepting PMs would be the default, but I thought I may as well test it. The result surprised me. Seems an odd default to not accept PMs.