I had the same problem and did not like the IMAP accounts.
This is a post i started back then, and here is what i did
»Office 2013 and Charter mail
by default Outlook 2013 will auto setup your Charter e-maill accounts as IMAP type, and that means it no longer will use the PST file format and will use the new OST file format.
It also created a different mailbox and OST file for each account i setup. I did not like that as i had all my accounts setup to delivery mail to one inbox in my PST file in outlook 2010.
I found that if you did the manual setup you could still chose POP and point it to a PST file, it takes a little longer to setup but its much better IMHO. So now all accounts from Charter will go into one Inbox in One PST file and i don't have to click each account to view the 10 folder each just to check new e-mails in each account.
I see you are having send problems.
You must set the out going server to smtp.charter.net