is filing a harassment charge legal under these circumstances and what is the process?

I sent an email to a friend,she calls my boyfriend and argues with him and responds to email. she was mad and called police,I never talked to them just saw the message and was very confused. I sent another email and then charges were pressed-Im assuming because the sheriffs office called again, I am not sure how this is legal?doesnt a restraning order or no contact order need to be in place first..I was told by the sheriff that I will have to go to court to prove no wrong doing? but it seems strange that someone can file w/ no proof and drag me to court over fighting over emails?? and I will add no threats were made whatsoever. I also think she set up a fake email in my name to further her "harassment" case because she is mad and wants revenge im guessing...is any of this legally possibl