In this blog, I am going to tell you what is SMTP Server, and how SMTP Server exactly works in bulk email marketing. SMTP stands for Simple Mail Transfer Protocol. In a layman terms it is like a small language which consists of only few words. This language is used by the sender of the email to send email to the receiver of the email. In the real world, both the sender and the receiver are actually an application or so called computer programs. In technical terms, sender is called SMTP client and the receiver is called as SMTP server.