To manage Exchange Online, you have various options available:
- PowerShell – you have to install first Microsoft Online PowerShell
- Exchange Management Shell
- Exchange Control Panel
However, even if the most complete tool is PowerShell, this tool is not very easy to use for everyone.
Moreover, many operations can be done only through the PowerShell.
So to assist customers in managing Exchange Online, Microsoft has provided a GUI tool to create shared mailbox – the most requested (and in some way the most difficult) mailbox management operation.
Currently, this tool is granting permission to the shared mailbox to a security group.
To know more about this tool and how to use it http://community.office365.com/en-us/w/exchange/1712.aspx
To download the tool http://community.office365.com/en-us/f/183/t/45006.aspx
The ‘classic’ way to create shared mailbox http://help.outlook.com/en-us/beta/ee441202.aspx