Email from Microsoft.. bogus or legitimate?

From: Garth Mawhinney (blooie427_at_rogers.com)
Date: 09/26/03 

Date: Fri, 26 Sep 2003 06:40:33 -0700

Good Day to you....
In the recent past I have been deleting e-mails which
showed the sender as being Microsoft.
The content descriptions were something like "install
patch immediately" and similar words.
I considered them as being possible viruses until I saw a
program originating in the UK which more or less treated
them as legitimate.
I checked with Windows Update and their search of my
computer didn't call for an update...
Can anyone comment?

Thanks in advance..