Sorry maybe I am stupid but I don´t know how to select several files in File Manager or several mails in Pantheon Mail
In Files, there are several ways to do this. Assuming you are using the default grid view you can:
With the mouse
- Select each item by clicking on the tick emblem that appears when you hover over it or
- Hold down the
<Ctrl>key and click anywhere on each item you want to select or
- Hold down the
<Shift>key and click anywhere on the first and last item you want to select. All items in a linear sequence between these two items will also be selected or
- Press and hold down the primary button over whitespace and drag the pointer to create a selection rectangle (rubberband). Any item this includes will be selected.
With the keyboard alone you can
- With the arrow keys. move the cursor to the first item to select. Hold down the
<Shift>key and move the cursor to the last item to select - all items in between in a linear sequence will be selected or
- Move the cursor to the first item to selected. Hold down the
<Alt>keys. Move the cursor to the next item to select. Press
=to select that item. You can also deselect items in the same way by pressing the
- You can select all items with the shortcut
- You can invert any existing selection with the shortcut
These methods work pretty much the same in the other views except for rubberbanding you click on the filename or any other column (not the icon) to commence.
I do not know about Mail - I do not use it but some of these methods might work.