Sharing Calendars with Exchange While Using POP Email

[thirtydash9]

Hi,

I need to enable Outlook (2003 on XP) calendar sharing for myself and another user. We both have Exchange listed in the email accounts, though we are actually using POP email and this account is also listed. Outlook does not give us the option of sharing our calendars (it's grayed out in the menus).

Any ideas?

Thanks -