Message from wow gm

Thank you, Keriam.

Q u o t e:
In game, you would receive a popup tooltip stating that a "Blizzard GM would like to talk to you". Clicking the window will open a new chat window where carry out the conversation with the GM.

This is correct, Aledra. You can find the details as to how it will look in-game at this Knowledge Base article:

I received an in-game whisper telling me to visit a website to claim a free reward. Is this a scam?
http://us.blizzard.com/support/article/30829

Q u o t e:
Out of the game, you might receive an email, but never in this email will they ask you to verify your account information by logging to a website.

Just because the email appears to be from Blizzard does not mean it is. Be sure to review the email headers if you are curious:

How to Identify Fake or Phishing Emails
http://us.blizzard.com/support/article/25133

Continue to utilize the "Report Spam" feature in game as well.