Thanks for using the forums to get this issue with your email looked into, I am sorry if this has been causing some frustration. I would be more than happy to help you resolve this. I have a link to another community post from one of our lead members who is an expert with Email Issues. Have a look Outgoing Authentication Issues and follow RavenStar's advice on his post, it should help get your email back up and running.
However, if you go through all the steps and it still doesn't help, please come back to me and I will try to help further!