Is there really no associated context? Does the message not display when you do a certain action? Does the message not lead you somewhere where you can deal with this "Campaign for expired accounts", whatever it is?
I'm afraid I don't know what it could mean. "expired accounts" is clear enough, of course, but I don't know why "campaign". It is not an expected word in association with "expired accounts". Grammatically it could be either a noun or a verb.