First of all let us see How email system is working over internet.
The email is sent on internet as shown in below picture
So Here The Sender i.e firstname.lastname@example.org is sending a mail to email@example.com. so the sender will type the mail and click on
send button and the mail will go to SERVER1.com whereSERVER1.com will forward the mail over internet and the internet
will search the firstname.lastname@example.org email ids server and send it to SERVER2.in and the the SERVER2.in will search for
the email@example.com in their own database and then the mail will be forwarded to firstname.lastname@example.org and when the XYZ user
login to their account they will see an email in their inbox which is from email@example.com.
Now How To send the fake mailTo send fake mail We need to Bypass the firstname.lastname@example.org and SERVER1.com both and directly send an email over
So for that we will use a .php script as php has a function mail(); which can send email to any one without the
SERVER1.com and directly delivering the mail to SERVER2.in and then SERVER2.in will search for the email@example.com in
their own database and then the mail will be forwarded to firstname.lastname@example.org and when the XYZ user login to their account
they will see an email in their inbox which is from email@example.com.
Now How to check When you receive such mail.Step 1:- First of all open the mail.
Step 2:- Now Click on the downward arrow near reply button. and click on show original.
Now check for The received from field on the page opened.
and see who has sent you the email , here firstname.lastname@example.org is the sender.
so in the received from field check that there must be microsoft.comand not any other thing.
this was fake mail as there was outgoing.x10hosting.com and so the mail is fake as there is no microsoft.com here.
If you know how to do it ,Then you must know how to prevent it...