What is an SMTP Server?

How do SMTP servers work and what is a fake smtp server

smtp api

If you ask anyone whether they can send an email, a good percentage of them will answer in the affirmative. People do not realize that the behind-the-scenes of receiving and sending emails are a technical system. What assists you in sending mail is called a server. A server handles particular services; in this case, an email server deals with mails only. The email server division is into two, the outgoing and the incoming server.

The outgoing server is what is called an SMTP server. Let's see what it is.

What is SMTP Server?

SMTP is initial for the Simple Mail Transfer protocol. Its server is a computer or app that assists in the sending of emails. Its function is receiving emails or commands from a client and relaying them to another SMTP server and finally to another incoming email server.

How Does SMTP Server work?

Below are some of the steps of sending an email and the input of an SMTP server.

  • There is something called a mail user agent which can either be your email client or an app. This MUA --initials for mail user agent- conducts an SMTP handshake which happens when it links to the SMTP server of your domain. An excellent example of an email domain name is smtp.mailslurp.io. There are several ways to connect, but the most common is through an SMTP port. Once the connection is ready, then the process starts. For more SMTP connections, visit our website mailslurp.com

  • The client then posts the data needed to the server. The data comprises of email addresses of both the sender and receiver, the email body, and any necessary email attachments

  • The SMTP server, or to be specific, the mail transfer agent, goes ahead to countercheck whether the domain name of the sender and receiver are similar. Similar domain names are sent directly to the recipient's POP3 or IMAP server. When the domain names are different, then the following process happens, which is the communication of the SMTP to the Domain name server (DNS)

  • After that, the DNS avails the receiver's IP address.

  • The second last step is where the dispatcher's SMTP server links to the recipient's and sends the email. If the recipient's server is Unavailable, maybe because the connection is low or crowded, the email is put in an SMTP queue. The SMTP queue is buffer storage where the emails are kept before they get to the recipient. The other option is that the email is kept in a backup server.

  • The last step is where the recipient's server collaborates the domain names and the incoming mail, then forwards it to the appropriate server

See, the behind-the-scenes process of sending an email can be a tad bit complex compared to just hitting the send button.

What is a fake SMTP server?

Yes, there is both a real SMTP server and a fake one. The fake one is also important in one way or another.

What is the difference between a real and a fake SMTP serve

A real SMTP server receives a command from a client address and sends it to a recipient. A fake one receives the order but does not send the email. It only emulates the sending, meaning there is no delivery

The importance of a fake

A fake SMTP server helps you test emails for your app or website. It is like a dummy for email sending.


You can compare an SMTP to a postman, only that the SMTP is digital. It is essential to note that the only role of an SMTP serve is dealing with outgoing mails.