Most experienced and legitimate marketers who use email marketing will tell you they practice permission-based email marketing. Who wants to be grouped in with the spammers pitching pharmaceutical panaceas or seeking your stateside assistance with a financial transaction?

However, in practice there are many large brands and companies who define "permission" at their convenience instead of the intended status of the recipient, and it is the recipient who should hold the cards on who they receive emails from.

A recent car buying experience that took place largely on the internet shed much light on how many companies view email marketing and their "right" to do so, regardless of your relationship with them (or lack thereof). After sending email inquiries to many dealers, I found that I was added to their "newsletter" database, regardless of whether I even had any communication with them, outside of the initial email. These were poorly done email campaigns, but the bigger and more important issue is their interpretation of permission. None was implied nor given. Making matters worse was the unsubscribe process involved sending an email to an address that did not work. So technically, this dealership not only is way off on best practices but also is violating CAN-SPAM.

"Permission" is defined by Merriam-Webster as the act of permitting and formal consent. This is very straightforward and hard to misinterpret. Yet, many marketers take the liberty to stretch this into a more open-ended and vague marketing relationship.

All email marketers should be aware of the potential downsides to this strategy.

Is it ever acceptable to email customers or prospects that have not granted permission for you to do so? Bear in mind that email marketing is like dating: if you have met the person before or have been introduced through a friend, then chances are better that you will hit it off.

Let's look at three common situations that may arise where a marketer might be tempted to send an email even though explicit permission hasn't been given, along with some additional guidelines to make sure your emails don't get you in trouble with the law.

Next: The stranger