Thanks for the reply, 2011 iMac 20.5 ", Mt. Lion, can't send email on Charter.net but can receive. AppleCare thinks it is a conflict of Charter.net and Apple Mail. I can see by some of the postings here that I/we am not alone. Many are having this problem with Charter. Any ideas will be explored.
We have gone to mobile me, gmail, hotmail, etc., instead of using Charter.net. Think we have been classified as "spam" senders by Charter even though we do a lot of not-for-profit emails and make no money from them. Charity organizations are what we work with. Suspect Charter wants us to move to that higher level of usage classification. They have blocked emails on occasion, even if denied by phone contact with them.
Local Apple computer technicians we have had contact with also do not use Charter.net because of conflicts with Charter's servers. These do not send goodly numbers of email as my wife and I do--50 or so at a time. Charter keeps saying it is an error in the email settings, but have had AppleCare walk me through the settings several times and doubt this very much.
Anyone resolved this without moving to a higher level of email usage for a higher charge? We may have to move to a higher usage because we are paying a fee for email but can not use it--at least we could use it then.
Thanks again--any ideas given will be explored,
mizzou