Frequently when using Lotus Notes 4.5 when one gets an E-mail message concerning a meeting or possible meeting, it is desirable to be able to continue having the E-mail view open as the same time as the calendar view. The problem is that "inbox" and "calendar" are two different views of the same database, so if when you switch to another view the first one goes away.
There are two solutions to this problem.
Select your E-mail database from your Workspace by double-clicing on the E-mail icon (the one with the drawing of a first-class postal letter in it).
On your E-mail window menu bar, select Window>>"Workspace at ...". This pops you back to your main Lotus Workspace.
shift-doubleclick on the E-mail icon. This gives a second window into your E-mail database, which you can then switch into the calendar view.
(My thanks to Betty Ashcraft for discovering this method).
While looking at your inbox in an E-mail window:
These steps need to be done the first time only.
Do this every time:
(My thanks to John Anderson for discovering this method).