Mail (Mavericks): About email accounts
You can use different types of email accounts in Mail.
With an iCloud account, you can use Mail on your Mac and have instant access to your messages and mailboxes on your other computers (with OS X v10.8 or later) and devices (with iOS 5 or later) that use iCloud Mail.
If you use iCloud Contacts, your VIPs and Previous Recipients list are available on your Mac computers (with OS X v10.8 or later) and iOS devices (with iOS 6 or later) that have iCloud Contacts turned on.
If you use iCloud Documents & Data, your rules, signatures, flag names, and Smart Mailboxes are available on your Mac computers (with OS X v10.8 or later) that have iCloud Documents & Data turned on.
If you turn off iCloud Contacts or iCloud Documents & Data, information is no longer updated on your Mac computers or iOS devices.
With IMAP accounts, incoming and outgoing messages are stored on a mail server until you delete them. When your account connects to the server, it’s synced so that the messages on your Mac are the same as those on the server. You can read and manage messages from any device that you use to access your account, and download messages or attachments to work with when you’re not connected to the Internet.
Microsoft Exchange accounts
These accounts are similar to IMAP accounts, in that messages are stored on a mail server and accessible from different computers and locations. You can use flags in an Exchange account with some limitations.
For an Exchange account to be set up in Mail, the Exchange server must support Exchange Web Services (EWS). Contact your server administrator for more information.