By Brian Clark

You ever been out with your pals having a good time, laughing so hard that the surrounding tables end up giving you the stink-eye?

Or maybe you host a knitting club at your house. You’re a band of obsessed knitting fanatics who can’t get enough of yarn, patterns and the latest celebrity knitting gossip.

One day a guy shows up in your living room mumbling about how the Lakers were totally robbed in the recent playoff series with the Dallas Mavericks.

This person is called the unwelcome guest.

In email marketing — if you aren’t known, liked, and trusted — you’re the unwelcome guest, and there is only instant and merciless deletion waiting for you.

The email inbox is sacred ground. We don’t want anyone coming... More...