For example, you want to add the Cc column in the current view, you can do as follows:

1. Open the specified mail folder (the Inbox folder in this case), and click View > Add Columns.

2. In the Show Columns dialog, please do as follows:
(1) Please select the specified category containing the column from the Select available columns from drop-down list. In this case, please choose All Mail fields;
(2) In the Available columns list box, please click to select the specified column you will add. In this case, please select Cc.
(3) Click the Add button.

3. Now the Cc column is added to the right list box. Please click to select Cc in the right list box, and click the Move Up button to move it to the proper position.

4. Click the OK button.

So far, the Cc column has been added to the current mail folder. See screenshot:

Notes:
(1) If the specified folder is in the compact view, you may not get the added column until turning off the reading pane or move it to bottom. You can click View > Reading Pane > Off or Bottom to turn off the reading pane or move it to the bottom of message list.
(2) You can click View > Reset View to restore the default view settings.

There are several methods to remove a column from the current view.

Remove a column from the current view with Add Columns command

Supposing the Inbox folder is displaying in the preview view at present, and you want to remove the Subject column from this view, you can do as follows:

1. Click View > Add Columns to open the Show Columns dialog.

2. In the Show Columns dialog, please click to select the column you will remove in the Show these columns in this order list box, and click the Remove button.

3. Click the OK button.

Now the specified Subject column is removed from the current view.

Remove a column from the current view with right-clicking menu

If the Inbox folder is in the single view or preview view, you can remove a column from the view with the right-clicking menu easily.
In the message list, right click the specified column header which you will remove, and select Remove This Column from the right-clicking menu.

Now the specified column is removed from the current view at once.

Note: If the specified folder is in the compact view, you cannot right click a column header until you turn off the reading pane or move it to bottom. You can click View > Reading Pane > Off or Bottom to turn off the reading pane or move it to the bottom of message list.

Remove a column from the current view with dragging and dropping

If the Inbox folder is in the single view or preview view, you can also easily remove a column with dragging and dropping.

At the top of the message list, click the specified column header that you will remove, drag it and drop out of the message list. Then the specified column is removed from the current view immediately.

Note: If the specified folder is in the compact view, you cannot drag a column header until you turn off the reading pane or move it to bottom. You can click View > Reading Pane > Off or Bottom to turn off the reading pane or move it to the bottom of message list.