Hey, what answers do you need?
Chapter
< Contents
Print

What is SMTP and how does it work?

SMTP (Simple Mail Transfer Protocol) is a protocol that is used to transfer emails between servers and clients. It is a text-based protocol that is based on the TCP protocol (Transmission Control Protocol).

When a user sends an email, it is transferred from a client program (e.g. Outlook or Gmail) to the sender's SMTP server. The sender's SMTP server then checks whether the recipient's e-mail address is valid and forwards the e-mail to the recipient's SMTP server. The recipient's SMTP server then delivers the email to the recipient's mail client.

An important aspect of SMTP is the ability to transfer emails between different email servers. This makes it possible to transfer emails from one server to another until they finally reach the recipient.

There are also extensions to the SMTP protocol, such as SMTP authentication, which increase the security of email transmission and allow users to log in to the email server before they can send or receive emails.

Example

An example of an SMTP transmission could look like this:

  1. A user, John, wants to send an email to his girlfriend, Sarah. He uses an email program such as Outlook or Gmail.
  2. John enters Sarah's e-mail address as the recipient address and writes the text of the message.
  3. John clicks on "Send" and his e-mail program connects to the sender's SMTP server (in this case John's e-mail provider).
  4. John's SMTP server checks whether Sarah's e-mail address is valid and forwards the e-mail to the SMTP server of Sarah's e-mail provider.
  5. The SMTP server of Sarah's email provider finally delivers the email to Sarah's email program.

In this example, the email has passed through two SMTP servers: that of the sender and that of the recipient. However, there may also be several SMTP servers involved when the email is forwarded from one server to another until it finally arrives at the recipient.

It is important to note that this is only an example and the actual transmission of emails may vary depending on the email provider and network configuration.

Tags: