Simple Mail Transfer Protocol (SMTP)

The Simple Mail Transfer Protocol (SMTP) regulates the sending of emails between mail servers. You can imagine it like the postman transporting messages from one location to another. SMTP ensures that the email is securely forwarded from one mail server to the next until it reaches the recipient.

When it comes to secure email communication, SMTPS provides encryption. This protects against eavesdropping attempts and ensures that only the recipient can read the message.

Today standard with TLS: Modern mail servers require the use of SMTPS or STARTTLS to ensure security when sending mail.

Classification in the OSI model:

• Application layer (Layer 7)
  SMTP and SMTPS are part of the application layer because they work directly with sending and receiving emails.