Rogers webmail will receive but not send

Hi all,
I currently have a Samsung Galaxy S4 running on the Telus network. I have only had the phone (my first Android device) for a few days. I originally setup my email and it functioned perfectly fine. Now I can receive emails but I can't send them. They all sit in the outbox saying that sending has failed. I have tried deleting and reloading the account on the phone to no avail. I am using the stock email app that came with the phone.
Can anyone help?