Lack of support for the Out Of Office Assistant (OOF) is one disadvantage of using POP3 or IMAP clients with Exchange. How can you give this functionality to POP3 and IMAP users? While you can't give OOF features to POP3 and IMAP clients directly, you can use Outlook Web Access (OWA) to work around this limitation.
OWA offers many of the features found in the full MAPI Outlook client, including OOF. Even if you can't get your POP3 and IMAP users to use OWA as their primary client, they can use OWA to set up OOF as needed, with minimal instruction.
If you haven't set up OWA before, this may be the time to try it. OWA won't consume a lot of server resources, particularly if your users only use it for OOF.
While not required, most administrators prefer to install OWA on a separate server. If you still use Exchange 5.5, you won't need to buy another Exchange Server license to install OWA on a separate server. However, if you're installing OWA on a front-end server in an Exchange 2000 environment, you'll need a separate license.