I wrote this for people on another popular mmo board I frequent. I know most people on this site are pretty familiar with such things but not everyone is as techno savvy as the rest.
I hope this helps at least 1 person.
Also my apologies for it being in BMP format, i created it at work using MSpaint and converting it to a JPG it would lose too much quality and look like crap.
Here are the links i listed so you don't have to type them out:
Go here if you are unsure how to access the full header information for your email service:
Message headers - Gmail Help
Trace the IP address of the originating sender (Official Blizzard emails will be sent from their email server which the location will say Irvine California or it may even say Blizzard.
IP Tracer, IP Tracker, IP Locator and other DNS tools
If you get an email that is encoded in base64 you can cope the body text and paste it into this website and it will decode what it says and you can see the URL that the masked links would have taken you too. (I use this to add them to my block list so If i try to go to the site my browser wont allow it)
Base64 Online - base64 decode and encode