Configuration Tabs in Zimbra

[mnbvmnbv]

Hi , i'm begginer in Zimbra y need to administrate the tabs when some specific user, for example : David , start his zimbra.

For exmaple, i want that David, when he starts his zimbra mail, the first tab that appears in his mail was Calendar

and for other user, for example, John , was Task

and for other user, for example, Marc, was Mail


Anybody can help me ?

Thanks

pd .: excuse my poor english