Even with a bunch of fancy new protocols available out there to handle client e-mail communication, for a variety of reasons, many users continue to use the legacy IMAP and POP3 protocols. Exchange 2007 continues to provide support for these protocols, but there are a few things you should know before you take the plunge and transition your IMAP/POP3 users to Exchange 2007.
Start the services
Although they are installed, the IMAP and POP3 services are not started by default. You can start them through the services control panel, or by using the following commands, which configure the services to start automatically and then start the services:
set-service msExchangePOP3 -startuptype automatic
start-service -service msExchangePOP3
set-service msExchangeImap4 -startuptype automatic
start-service -service msExchangeImap4
Enable plain text authentication
Under a default Exchange 2007 installation, IMAP and POP3 only work when the connection from the client is secured. For many organizations, this is not a desirable configuration. In order to support typical POP3 and IMAP connections, you must change the IMAP and POP3 server settings to allow plain text logins. Since this tip is being written pre-SP1, IMAP, and POP3 cannot be configured from the GUI. Instead, you must use the command line to make necessary changes. After you make configuration changes, you must restart the IMAP and POP3 services.
Set-PopSettings -LoginType PlainTextLogin
restart-service -service msExchangePOP3
Set-IMAPSettings -LoginType PlainTextLogin
restart-service -service msExchangeIMAP4
Don't test with the administrator account
For security reasons, under Exchange 2007, you can't use the Administrator account with IMAP or POP3. If you're testing these services, make sure you don't use this account.