Would you like to change the default account within Zimbra? Follow the steps provided in this article on how to proceed.
Note: Your accounts are displayed on the left in the order that you set them up. The first account is the default account. The Default is the account that is opened when you launch Zimbra Desktop.
1. Open your Zimbra Desktop Client by selecting you desktop shortcut.
2. Located in the top right hand corner, select Setup.
Note: You maybe prompted with a confirmation dialog box. Choose OK to continue.
3. For each account, you have five options (Edit, Delete, Reset, Reindex and Reset-GAL). Next to the Account Name, there are two arrow pointing up (except for the default account at the top). Click on the arrow to move that account to the top of the list and make it the default.
4. Click on Launch Desktop open the new defaulted account.