Email problems outlook express

Hello,
I had been using outlook express for many years without any problems at all. Then one day I sent an email and it repeated it self about a 100 times. I tried everything I new including reloading the program and setup (i have other computers using outlook express and the set-up is the same), NO help. However now I can send but can not receive anything. That tells me my set-up is working for the most part . I am running XP my ISP is Charter Comm (they(Charter) say they do not support outlook express, that's BS) Can someone help me out. cogginscl@gmail.com