Message stuck in hotmail outbox

My hotmail account is set up with the default e-mail app on my RARZ HD operating with ICS. I have no problem receiving and sending emails except for one email which has been stuck in my outbox for the last 2 days. When trying to send it, I get the message "Connection problem. (Hotmail)." However, I am connected to hotmail and I have been able to send other messages today, but this one is still stuck there. I cannot open it, because "the message is being sent and cannot be opened". This is getting really annoying because my phone rings every few minutes to let me know I have a message that has not been sent. There is no way I see to delete that message. I went on my hotmail through Chrome to log in and out, which didn't change anything. No result neither by turning off my phone. What could I do?

Thank you