A person who writes an aggressive and/or offensive email to one or multiple people, pointing the 'finger of blame' and/or undermining them, then when they see these people in person, they act as if nothing has happened.
Jo sends an email to Kate stating:
"Hi Kate, Your suggestion for the end of year celebration sounds boring so we're going to go with my other idea. Jo."
Then when Jo walks into the kitchen at the same time as Kate, Jo acts like Kate's best friend, "Hey Kate, How are things in your area today?"... Kate thinks Jo is an idiot and coward.
Jo has been an Email Hero - Tough in email, gutless in person.