POP3 vs IMAP vs Exchange Connector

IMAP

The IMAP protocol, short for Internet Message Access Protocol version 4, is a newer Client-server protocol used for accessing email. Unlike POP3 the email messages are kept saved on the server. This allows multiple locations and multiple email client programs to access the mailbox. This allows for both private and shared mailboxes. The capability of storing folders on the server is also included in the protocol. When a message is deleted or moved to a folder, that change is accessible to all mail clients. IMAP does not include support for Global Address Books or Calendaring, although the LDAP protocol can be used for Global Address Books and the vCal protocol for Calendaring.