If your users already have a common POP, IMAP, or SOAP email client that comes with Linux or Windows, they can continue to use it to access their GroupWise mailboxes. Users of non-GroupWise email clients retain the feature sets of their familiar email clients, but many GroupWise features are not available to such users because they are not offered in POP, IMAP, and SOAP email clients. For example, calendaring is available only if the POP, IMAP, or SOAP client supports iCal.