SMTP relay services work in a similar way. The sender’s message is sent to an SMTP server and placed in a virtual envelope. The SMTP server identifies that the recipient’s domain is not the sender’s domain, so relay services send it off to the recipient’s main email server that handles incoming messages.

What are SMTP gateways?

The Simple Mail Transport Protocol (SMTP) is an internet standard used to send, receive and relay email messages. SMTP gateways perform actions on email, such as spam filtering, that can help protect organizations from email-borne attacks.

How SMTP works step by step?

The functioning of an SMTP server can be broken down into two steps. The first step includes verification of the computer configuration through which an email is sent and granting permission for the process. In the second step, it sends out the message and follows the successful delivery of the email.

An SMTP server is a computer or an app that is responsible for sending emails. It functions following the Simple Mail Transfer Protocol (SMTP). An SMTP server receives emails from the email client. Then it passes them on to another SMTP server and relays them to the incoming mail server.