There are many email scams and people are constantly working on ways to fool you into revealing your bank details, login details to online services and so on. You need to be aware of the dangers and how to avoid them. Here is a typical email that tried to fool me into revealing my Apple ID - the username and password used to log into Apple services like iTunes. You might get a similar one, so take a look and learn how to spot the fakes.
An email always has a From: that contains the sender's email address and sometimes it even contains a proper name. However, this is not an excuse to end an email improperly and not include a signature. A signature can contain more than just your name and it is an essential component of an email message. You may not have realised it, but you can create impressive signatures in Mail in OS X on the Mac.