Well I am not entirely sure this is a good thing...
If you have an email or a series of emails and you want to share it/them then you can email it to post@moomeo.com. You then get a link which you then share (not by email - could have done that in the first place..). What this link enables you to do is to put the email onto social networking sites such as Twitter and Facebook.
I can think of a number of ways this might be useful, especially if you don't have a blog or website you can easily update and then link back to. On the other hand, it could be a nightmare for corporate media and IT managers as emails find their way into a more viral social media system.