Block undesired contacts like competitors

Many CRM tools have a way to block contacts that you don't want to ever send emails to. This kind of tool is great to block competitors, but also others for example, who like to steal content without citing us as the source. We have developed a list where we block people either by entire domain (like a competitor company) or by individual email addresses (like people who put gibberish for contact info, or who steal our content and pass it off as their own). It is essential for protection of intellectual property to have a way to prevent and/or discourage undesirable email addresses and domains from being able to interact with us. No, such a tool cannot entirely stop them, but it can certainly slow them down considerably.