Disable accounts can be done using Send/Receive group configuration.
1.Open Send/Receive Groups (CTRL+ALT+S) or browse to
Tools < Options > Mail Setup > Send/Receive
2.In the Send/Receive Groups click "edit"
3.In the left pane, select the requested account to modify the send/receive settings.
4.In the Folder Options disable the option for “Receive mail items”.
5.Press the OK for all windows.