If you can sort your Outlook inbox items you can do it by clicking the column title that you want to use to sort them. For example, to sort them by date you just need to click on Received column and they will be sorted in descending order, and if you click on it again, in ascending order.
But, what do you do if you want to sort by two columns? It is very simple, you just need to click on the first column, hold down the [Shift] key and then click on the second one. A small up or down arrow will appears on both columns to indicate that you are sorting the folder by these columns.
For example, if you want to group your mails by sender and by size, you should click on From column, hold down [Shift] key and then click on Size column. This should be the result:
Angel Perez Palacios 