When viewing emails in Outlook 2010, it shows the message subject, date, but not the size. How can I have it show the size in a column as well?
To view the size of a single email
Open the email you wish to view the size for by double clicking on it so that it opens in a separate window. Then click File on the top left corner, and then click Info. You will see a button titled Properties on the right and the heading "Size" under it.
To view the email sizes of all the emails
You need to change the view type. While viewing emails in Outlook, click the View button on top of the screen, click Change View on the left, and then click Preview on the right.
While in Preview view you can view the email sizes of all the email messages, and if you wish to do so you can click the Size column to sort them all by their size in either ascending or descending order. This allows you to see which emails take up a lot of space and you can select them and delete them, if you wish to do so.
There are of course other view types in Outlook. You may for example want to try out the Single view. Unlike the Preview view, this view will allow you to see the contents of the emails and not just their properties. It's mutch like the default view. The default view is called Compact. This is the one you want to choose if you wish to set things back to what they were before.
To create your own view type
You can of course also create your own custom views in Outlook 2010. You will find the settings for this by going to View button again, then Change View, and then you click the Manage Views option.
To view email sizes in the Compact view
You can view email sizes even when you're in the Compact view. All you have to do is click and drag the divider that divides your list of emails with the reading pane. By dragging it to the right it will make your reading pane more narrow but on the other hand it will make your list of emails wider and this results in more columns appearing on top of the list, including the Size column.
To sort emails by their size whithout changing view type or the reading pane
If you want to, you can also sort your emails by their size right in the Compact view. All you have to do is right-click on the column that says "Arrange By" and choose "Size". You will also find this option by clicking on the View button on the top right of the window, and in the section that says "Arrangement" click on "Size".
The default setting in Outlook 2010 is to sort emails by the date they were received.
You can also use the field chooser to add a Size column to the header row. Right click the header row and select Field Chooser. The Field Chooser should by default open to "frequently-used fields." Scroll down to Size then drag it to the header row and drop it where you want it to display (you should see a red arrow above the header row when you've got the field in a place you can drop it).
Here is an illustrated set of instructions. http://www.officetooltips.com/outlook/tips/adding_and_removing_columns.html