Trouble between ISPs?

Does anyone know a reason why this would happen with only one correspondent and no others? I called my ISP (Charter) but they have no idea.



I have a friend whose mail has trouble coming in, comes in and has trouble opening. When I reply, mail may or may not go. Just sits there with green bar but doesn't move. Finally, an error message will come up saying there has been an error and give me a choice to Retry or Cancel. If I cancel or hit X, it kills my letter totally. Once, a bit ago, there was actually another button on that error message saying change password. Why would I do this when the problem is only with one correspondent?



And all this only happens off and on. Not always. But in spells of some hours at a time. Yesterday, it started early morning and lasted up to mid-afternoon and then things smoothed out and went fine. Today, everything was fine until about noon. We've been having trouble ever since. My ISP tech people cannot give me any reason.



This has been going on for two or three weeks now. A mystery. Does anyone now any reason for such?



Oh, forgot to say only at my ISP. I also use Gmail and we have no trouble there.



Thanks.