When I turn off Chat, the space on the right side of my Gmail Window is blank. I have vertical split enabled and want the text to fill the blank space. How do I shrink the space on the right of the Gmail window after turning off "Chat"?
The default location of the chat widget is at the left. In order to show it in the right, the user should enabled the lab "Chat on the right".
In order to get rid of the widgets right panel go to https://mail.google.com/mail/u/0/#settings/labs and disable the "Chat to the right" lab. Don't forget to click on the save button before leaving the labs settings page.