I always wonder what is the right response to people reaching out for guest posts. Most of the time I feel they are just fishing for attentions. So, ignore and mark them as spam? Or be patient, read and decline humbly? Or maybe inform them politely that you are marking them as spam, and then mark as spam.
I am not the one to do the last option here. But I will get fed up someday and that will be my option.