Can anyone tell me if cyber bullying is 3 ppl ganging up on 1 person, humiliating, blaming on cruel emails?

I have 3 people who are cyber friends and on myspace together, so when one talks to me, she runs to the others and tells them what I say or reply to her emails. Then, I get cruel emails or myspace messages from the others, too, telling me I am fake and that I am acting like I am in high school, telling me to get a life and quit talking about them. One would send me emails about what a bad babysitter I was, that I wouldn't brush their child's hair or teaching her anything, so I reply in defense of myself that she was incorrect and that I always brushed her hair and we went over ABC'S and 123's and tried to learn to write her name, etc. She would show her family and co-workers my emails of response and would tell me they think I am rude and a bad person. Now, this person has the two new friends doing the same. They are not on my myspace list and they are blocked on my email accounts but somehow get through on myspace. They are the mom's of my grandchildren! is getting out of hand.