That makes perfect sense; Microsoft already has too much money. :-)

Seriously, Hotmail and/or Live are screwed up in more ways than dorking
around with checking browser and operating system. They're in so many
blacklists that a *LOT* of email sent from Hotmail/Live is simply
dropped as spam.

I didn't know that until one long-time friend called and asked why
I wasn't answering her email. Turned out (for me) Hotmail's spam score
as determined by SpamAssassin was above the spam threshold and the
email was simply discarded.

To solve that problem, I first created a Hotmail account and ran some
tests. Yep, everything from Hotmail is spam. So I had to explicitly
add certain correspondents' full email addresses into a whitelist on
my mail server to drop the spam score to around -95 or so.

Yahoo's email arrives with a spam score around 1.5, so that's much
better than Hotmail, but Yahoo still doesn't quite get it right.

Gmail email arrives with a spam score of 0; they did it right.