When I don't reply to their cold emails...because why would I?...they send a series of increasingly miffed-sounding followups, demanding to know the cost of posting an article for their client here on VFTP. (Well, they never refer to the blog by its name, only by its URL. They're somewhere in Lahore or Mumbai or Jakarta. They don't actually read the blog; they're just doing cut-rate web marketing for a third party.)
There's no point in replying "Bro, you can't write in my diary," so I just keep round-filing their emails until they take the hint.
Sometimes it can take a while.
.