"It's official. You've got a low fare to ________."

Do these emails annoy the crap out of anyone else? Every time I check a fare, I get an automated marketing email from Southwest that says "It's official. You've got a low fare to [city]." It makes it sound like an order confirmation, which is baffling. Moreover, I don't see a way to unsubscribe from just these emails. I created a Gmail filter for them, but really, that shouldn't be necessary.