|It sounds like you are dealing with a classical virtual bully. He's a tough guy when he is online, but not in person. The computer shields him from the responsibility that accompanies real interaction with another human.|
The first step is to approach the bully himself, and do so face-to-face. Let him know that his profanity is offensive, hurtful, and demeaning, and you want it to stop in all future communication with you.
If you continue to be targeted by his profanities, go to his manager. Let the manager know that these messages are creating a hostile environment in which it is increasingly difficult for you and some of your associates to work. Bring a few examples of the email messages with you. This paper trail can induce senior management to become more proactive in this area.
You can also suggest that management review its email policy and make sure that inappropriate messages, such as those that contain profanity, are clearly prohibited. The virtual bully should be encouraged to keep the following in mind: what would his family think about his messages, and what would a jury think about them?