Use Secure Sockets Layer (SSL): NO Authentication: password
User Name: email-name+your-domain-name.com Password: your email password
Dismiss the window by pressing "OK." Back in the "Accounts" pane, switch to the "Advanced" tab and do not check the box marked "Use SSL" towards the bottom.
Next you have to set the IMAP path prefix? Type INBOX (all caps).
Important Notes Exchange, IMAP, and iCloud accounts store their mailboxes and messages on the server; deleting these account types in Mail will not permanently delete messages from the server. However, if you are not completely certain that your account is one of those types, be sure to copy the mailboxes and messages you want to keep into an On My Mac mailbox, or save individual messages manually by selecting them and choosing Save As from the File menu.
Due to the many changes introduced with the latest version of Mac OS X Mountain Lion, you can visit Apple's office troubleshooting guide at: