Every time I send an email the receiver gets the email anywhere between 2 & 10 times.

I send an email once but in my sent box it is listed 10 times all saying sent at 2:51pm for example but speaking to the person I sent it to, they received the same email every ten minutes for the next two hours (presumably when I logged out).  

Hello,

Is it possible that the email exceeded your server size limits? Also please check for any rules that might cause this behavior, try turning them all off and sending a message to see if this behavior persists.