Email Accounts

We currently have two cox accounts for our property, one for the main house and one for the guest house.  The account for the main house is in my name, and the one for the guest house is in my wife's name, so her primary email address is associated with that guest house account. Recently, we were able to obtain the wireless signal from the main house in the guest house, so we only need that second account for TV in the guest house.  If we discontinue the second account direct internet service to the guest house, and use the wireless signal from the main house account, how can my wife's primary email address be transferred to that main house account as one of the 10 email addresses available on that account? 

I have also been told that if we disconnect the internet service from the guest house account, we can maintain her email account and email activity for a $9.99/mo. fee. Is this correct?  If not, we will need a Cox contact to transfer her email address to our house account after disconnecting the internet service at the guest house.  Thanks for your help in advance.