All of us sends emails to our friends and buddies from our email id and from our email they easily knows that we are sending them emails but what if you send an email to your friend from your other friends email id without knowing his password. Yes, it's possible their are some webs and servers that allows you to send email using any email address and you can easily send fake emails to your newbie friends who is just new in internet or don't know what happens actually? Well there are mainly two methods for sending fake emails,
Sending Fake Email using Open Relay Server
An open mail relay is a SMTP (Simple Mail Transfer Protocol) server configured in such a way that it allows anyone on the Internet to send Email through it, not just mail destined to or originating from known users. An attacker can connect the Open Relay Server via Telnet and instruct the server to send the Email. It requires no password to send the Email.
Sending Fake Email using Web Scripts
Web languages such as PHP and ASP contain the mail sending functions which can be used to send Emails by programming Fake headers i.e. From: To: Subject: There are so many websites available on the Internet which already contains these mail sending scripts. Most of them provide the free service, Some of them are: