Instead of buying cards and spending all that money mailing greeting cards, ask your company to donate what they would have spent to an organization or several selected by the employees?   You could even make it democratic and have everyone vote on their favorite.  

On the other end, maybe we could let the businesses that send those cards know that the snail-mailed sentiment is apprciated, but that, as suggested, they might find a better place for their money and say so in that ecard.

I worked for a bank that basically does what Aimee suggested, albeit for social reasons more than environmental ones.  Instead of sending the same lavish 5"x7" gold-foil-and-tissue cards that our competitors sent, we sent smaller and less elaborate cards, cards designed by a local artist and printed at a local shop, and donated the difference to a local charity selected by a panel of employees.

The idea was pretty well-received; our customers understood that we cared, both about them and about our community.  I never once heard a depositor complain that our Christmas card wasn't flashy enough.

-- A.

I'd actually like to hear more about the efficiency of the Post Office deliveries.
At first, I thought, yea, they should definitely invest in alternative fuel vehicles(those little cars they drive around could easily be golf carts, right?). On the other hand, they have a pretty well planned out route, they walk a lot, they deliver multiple things at once...seems to me to be a pretty well oiled machine. I doubt anyone's regular daily errands are as efficient as the post office deliveries.

It may depend on the nature of the business. I get birthday cards online from 2 or 3 ebusinesses... and they actually make me feel warm and fuzzy. Small businesses. Leftie newsletters. And I'm a lonely old women.
But a card from, say, Walmart (big business) would not feels so fuzzy. Or at least, if fuzzy, cold. And slimy. Likewise my government or my phone company.