sudden problem with mobile me/icloud mail on mac

For about a week, I've been having trouble with my mobile me email on my Mac (running Mountain Lion). I get a message saying error on server & giving pathname. I also now have some difficulties logging in online - getting again a connection problem. The problem is intermittent but regular, I've never had this before and have not changed any settings that I know of! Only different thing I've done lately is set up mobile me on my android (which doesn't work properly, can't send email this way). Email is coming in fine to my phone, even when I'm having difficulties on my Mac. Any suggestions to fix welcome. R.