My wifes friend cannot send email when using Hotmail. She can receive mail just fine. She says that she gets a message that says “Please check your email address for correct format.” or something like that, and the words are jumping up and down on the screen. I am going there next Sunday, and if I can find answers here, it will help a lot. It sounds like a virus to me.
I just sent a message in Hotmail, so it’s not the site. Other than that, I can be of no help.