[Users] How to stop spacebar from going to next message?

[Adam Nielsen]

Hi all,

I have an annoying tendency to rest my thumb on the spacebar while I'm
reading e-mails, and before I know it, the key gets pressed and 15-20
unread e-mails are suddenly marked read and I have no idea which ones
I've actioned and which are still waiting for a response.

Is there some way to stop the spacebar from marking e-mails as read
when you haven't read them, and you've just held the key for a second
or two by accident?

I tried assigning the Help/About menu item keyboard shortcut to be the
spacebar but that doesn't work, pressing the spacebar just opens the
menu item without assigning a shortcut key.

Is there any other way to change the behaviour of the spacebar?

Many thanks,
Adam.