Most of the emails asking you to click on the link to provide username/password are bogus. Another way to see if the link is bogus mouse over the link and at the bottom left of your web browser there will be a target link of where the link actually pointing you to.
For example, here is a link to youtube, but the link will say whitehouse:
As you mouse over my link, you can see at the bottom left that the true link is actually going to youtube and not whitehouse.
In your post, the e-mail pretends to be mountbuzz staff, but the actual link is going to socialknowledge.com url, which is obviously not mountainbuzz.
Hope this helps.