We use outlook in the office as the primary means of communication - I think it is more geared towards this environment, i.e. it is designed an internal communication tool (as well as external too of course) by setting up meetings and appointments with people, and viewing other peoples folders etc, as well as those mentioned above.
At home however, I just want something to check POP/SMTP mail etc, without all the other facilities of Outlook.
Regards,
Maz