My husband talks to his exwife every few weeks, just a civil "hey how ya doing" kind of thing. I have no problem with this, as we all grew up going to the sames schools etc. His exwife is in a relationship... the relationship that ended her marriage to my husband (she cheated on him and is still with to man she cheated with)... anywho...

My husband received an email from his exwife's boyfriend telling him to stop talking to her or he was going to show up on our doorstep with a baseball bat.

The fact that he went into detail (baseball bat)... and didn't simply ask him to stop talking to her, has got me scared. My husbands exwife emailed him a day later and apologize for the email (but I don't think she knew what was said in the email)

I have a 5-year-old daughter, and am not sure what this crazy guy is capable of. Is one threat enough for us to get a protection/restraining order against this guy so I can ensure my families safety??

I think restraining order may vary state to state.. if you still have a copy of that email I would take it to the local police department and ask them for guidance.

One single e-mail threat probably won't do it. If it becomes a pattern, however, or if he actually tries to physically confront your husband, then you probably could get a restraining order. But just from the standpoint of prudence and not just where the law is concerned I don't necessarily think your husband should keep on talking with his ex (except as necessary to comply with visitation for the children, if there are any involved.)