Many of them do not seem to have any purpose at all (except to possibly annoy) because they neither advertise a product nor contain any clickable links.
Here are some shining examples:
evieNice collections of names, I must admit. Perhaps I should continue collecting these spams and some day put together a book of first name suggestions for parents to be.
Here's what arrived today, with the subject "Dont be left behind because of bad health":
Urgent question of the night.
That one came from my dear concerned but, alas, unknown friend Ephrayim Gordon at email@example.com.
An urgent question of whatever indeed!