Is an interview follow up email ever a bad idea?

In the vast majority of cases, an interview follow up email is a good idea. This email can help you stay in contact with the decision makers that will be deciding whether or not you get your job. The only possible exception to this rule would be if your interviewer specifically asked you not to contact them. In some cases, you might be dealing with an interviewer or a company that does not use email. If this is the case, a more personal follow up might be better, such as making a phone call.