Email is traditional method for communication with people but it is popular this time also and become famous. i am assuming that every one those using internet, have at least one email id. no matter that you have free email or professional email both are same. i have already written about free email and professional email. you can read detail about free email vs professional email here .
Maximum people are using free email like G-Mail,yahoo mail,hot mail,outlook,live and rediff mail etc.but do you know what is importance of email? it is also become marketing platform for internet marketer and another side it is become best method to hack account for hackers.
If you received an email then it is necessary to know that email is sent from where?what is IP address of sender, is this email is fake or real.All these information can extract from Header of email.so if you have a question that How to trace IP address of received email then read this article.
In example i am using Rediffmail . now I logged in and open email which is sent from Facebook, See this preview :
Now Click on Show full Headers.then a pop up window will open and look like this:

from above image you can see many line of information , all are important and known as Header but if don’t want read all then read only three points that is marked.In first point you can know date and time of received email,(this can also know in inbox of mailbox) , In second point you can know IP address of received email and lastly in third point you email is written. here i have removed my tested email address name.